(*^ ::[ Information = "This is a Mathematica Notebook file. It contains ASCII text, and can be transferred by email, ftp, or other text-file transfer utility. It should be read or edited using a copy of Mathematica or MathReader. If you received this as email, use your mail application or copy/paste to save everything from the line containing (*^ down to the line containing ^*) into a plain text file. On some systems you may have to give the file a name ending with ".ma" to allow Mathematica to recognize it as a Notebook. 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automaticGrouping; currentKernel; ] :[font = input; initialization; preserveAspect] *) Exercises on Systems of Differential Equations (* :[font = input; initialization; preserveAspect] *) $Post:=If[MatrixQ[#],MatrixForm[#],#]& (* :[font = input; initialization; preserveAspect] *) Exercise 1 (* :[font = input; initialization; preserveAspect; startGroup] *) M=Table[i+j,{i,4},{j,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, 3, 4, 5}, {3, 4, 5, 6}, {4, 5, 6, 7}, {5, 6, 7, 8}}] ;[o] 2 3 4 5 3 4 5 6 4 5 6 7 5 6 7 8 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]//Together]; P//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{2, 1, (-145 + 27*30^(1/2))/(-265 + 48*30^(1/2)), (145 + 27*30^(1/2))/(265 + 48*30^(1/2))}, {-3, -2, (-185 + 34*30^(1/2))/(-265 + 48*30^(1/2)), (185 + 34*30^(1/2))/(265 + 48*30^(1/2))}, {0, 1, (-225 + 41*30^(1/2))/(-265 + 48*30^(1/2)), (225 + 41*30^(1/2))/(265 + 48*30^(1/2))}, {1, 0, 1, 1}}] ;[o] -145 + 27 Sqrt[30] 145 + 27 Sqrt[30] ------------------ ----------------- 2 1 -265 + 48 Sqrt[30] 265 + 48 Sqrt[30] -185 + 34 Sqrt[30] 185 + 34 Sqrt[30] ------------------ ----------------- -3 -2 -265 + 48 Sqrt[30] 265 + 48 Sqrt[30] -225 + 41 Sqrt[30] 225 + 41 Sqrt[30] ------------------ ----------------- 0 1 -265 + 48 Sqrt[30] 265 + 48 Sqrt[30] 1 0 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=(Inverse[P]//Together).M.P//Together; T//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 2*(5 - 30^(1/2)), 0}, {0, 0, 0, 2*(5 + 30^(1/2))}}] ;[o] 0 0 0 0 0 0 0 0 0 0 2 (5 - Sqrt[30]) 0 0 0 0 2 (5 + Sqrt[30]) :[font = input; initialization; preserveAspect; startGroup] *) z=Table[Z[i][x]/.DSolve[Z[i]'[x]==T[[i,i]]Z[i][x],Z[i][x],x] \ /.{C[1]->K[i]},{i,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{K[1]}, {K[2]}, {E^((10 - 2*30^(1/2))*x)*K[3]}, {E^((10 + 2*30^(1/2))*x)*K[4]}}] ;[o] K[1] K[2] (10 - 2 Sqrt[30]) x E K[3] (10 + 2 Sqrt[30]) x E K[4] :[font = input; initialization; preserveAspect; startGroup] *) y=P.z//Together//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{(34*K[1] + 17*K[2] - 7*E^((10 - 2*30^(1/2))*x)*K[3] - 3*30^(1/2)*E^((10 - 2*30^(1/2))*x)*K[3] - 7*E^(2*(5 + 30^(1/2))*x)*K[4] + 3*30^(1/2)*E^(2*(5 + 30^(1/2))*x)*K[4])/17}, {(-51*K[1] - 34*K[2] + E^((10 - 2*30^(1/2))*x)*K[3] - 2*30^(1/2)*E^((10 - 2*30^(1/2))*x)*K[3] + E^(2*(5 + 30^(1/2))*x)*K[4] + 2*30^(1/2)*E^(2*(5 + 30^(1/2))*x)*K[4])/17}, {(17*K[2] + 9*E^((10 - 2*30^(1/2))*x)*K[3] - 30^(1/2)*E^((10 - 2*30^(1/2))*x)*K[3] + 9*E^(2*(5 + 30^(1/2))*x)*K[4] + 30^(1/2)*E^(2*(5 + 30^(1/2))*x)*K[4])/17}, {K[1] + E^((10 - 2*30^(1/2))*x)*K[3] + E^(2*(5 + 30^(1/2))*x)*K[4]}}] ;[o] (10 - 2 Sqrt[30]) x (34 K[1] + 17 K[2] - 7 E K[3] - (10 - 2 Sqrt[30]) x 3 Sqrt[30] E K[3] - 2 (5 + Sqrt[30]) x 7 E K[4] + 2 (5 + Sqrt[30]) x 3 Sqrt[30] E K[4]) / 17 (10 - 2 Sqrt[30]) x (-51 K[1] - 34 K[2] + E K[3] - (10 - 2 Sqrt[30]) x 2 Sqrt[30] E K[3] + 2 (5 + Sqrt[30]) x E K[4] + 2 (5 + Sqrt[30]) x 2 Sqrt[30] E K[4]) / 17 (10 - 2 Sqrt[30]) x (17 K[2] + 9 E K[3] - (10 - 2 Sqrt[30]) x Sqrt[30] E K[3] + 2 (5 + Sqrt[30]) x 9 E K[4] + 2 (5 + Sqrt[30]) x Sqrt[30] E K[4]) / 17 (10 - 2 Sqrt[30]) x 2 (5 + Sqrt[30]) x K[1] + E K[3] + E K[4] :[font = input; initialization; preserveAspect; startGroup] *) y//N (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0.05882352941176470589* (34.*K[1.] + 17.*K[2.] - (23.4316767251549834*K[3.])/ 2.718281828459045235^(0.9544511501033222691*x) + 9.431676725154983404* 2.718281828459045235^(20.95445115010332227*x)*K[4.])} , {0.05882352941176470589* (-51.*K[1.] - 34.*K[2.] - (9.954451150103322269*K[3.])/ 2.718281828459045235^(0.9544511501033222691*x) + 11.95445115010332227* 2.718281828459045235^(20.95445115010332227*x)*K[4.])} , {0.05882352941176470589* (17.*K[2.] + (3.522774424948338865*K[3.])/ 2.718281828459045235^(0.9544511501033222691*x) + 14.47722557505166113* 2.718281828459045235^(20.95445115010332227*x)*K[4.])} , {K[1.] + K[3.]/ 2.718281828459045235^(0.9544511501033222691*x) + 2.718281828459045235^(20.95445115010332227*x)*K[4.]}}] ;[o] 23.4317 K[3.] 0.0588235 (34. K[1.] + 17. K[2.] - ----------------- + 0.954451 x 2.71828 20.9545 x 9.43168 2.71828 K[4.]) 9.95445 K[3.] 0.0588235 (-51. K[1.] - 34. K[2.] - ----------------- + 0.954451 x 2.71828 20.9545 x 11.9545 2.71828 K[4.]) 3.52277 K[3.] 0.0588235 (17. K[2.] + ----------------- + 0.954451 x 2.71828 20.9545 x 14.4772 2.71828 K[4.]) K[3.] 20.9545 x K[1.] + ----------------- + 2.71828 K[4.] 0.954451 x 2.71828 :[font = input; initialization; preserveAspect] *) Solution check: (* :[font = input; initialization; preserveAspect; startGroup] *) D[y,x]-M.y//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0}, {0}, {0}, {0}}] ;[o] 0 0 0 0 :[font = input; initialization; preserveAspect] *) Exercise 2 (* :[font = input; initialization; preserveAspect; startGroup] *) M=Table[Mod[i+j,2],{i,4},{j,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 1, 0, 1}, {1, 0, 1, 0}, {0, 1, 0, 1}, {1, 0, 1, 0}}] ;[o] 0 1 0 1 1 0 1 0 0 1 0 1 1 0 1 0 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-1, 0, -1, 1}, {1, -1, 0, 1}, {-1, 0, 1, 1}, {1, 1, 0, 1}}] ;[o] -1 0 -1 1 1 -1 0 1 -1 0 1 1 1 1 0 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-2, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 2}}] ;[o] -2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 :[font = input; initialization; preserveAspect; startGroup] *) z=Table[Z[i][x]/.DSolve[Z[i]'[x]==T[[i,i]]Z[i][x],Z[i][x],x] \ /.{C[1]->K[i]},{i,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{K[1]/E^(2*x)}, {K[2]}, {K[3]}, {E^(2*x)*K[4]}}] ;[o] K[1] ---- 2 x E K[2] K[3] 2 x E K[4] :[font = input; initialization; preserveAspect; startGroup] *) y=P.z (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-(K[1]/E^(2*x)) - K[3] + E^(2*x)*K[4]}, {K[1]/E^(2*x) - K[2] + E^(2*x)*K[4]}, {-(K[1]/E^(2*x)) + K[3] + E^(2*x)*K[4]}, {K[1]/E^(2*x) + K[2] + E^(2*x)*K[4]}}] ;[o] K[1] 2 x -(----) - K[3] + E K[4] 2 x E K[1] 2 x ---- - K[2] + E K[4] 2 x E K[1] 2 x -(----) + K[3] + E K[4] 2 x E K[1] 2 x ---- + K[2] + E K[4] 2 x E :[font = input; initialization; preserveAspect; startGroup] *) D[y,x]-M.y//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0}, {0}, {0}, {0}}] ;[o] 0 0 0 0 :[font = input; initialization; preserveAspect] *) Exercise 3 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{1,-2,-2,-2,-2}, \ {2,6,4,4,4}, \ {-3,-6,-6,-10,-10},\ {1,2,3,6,1}, \ {1,2,3,4,9}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, -2, -2, -2, -2}, {2, 6, 4, 4, 4}, {-3, -6, -6, -10, -10}, {1, 2, 3, 6, 1}, {1, 2, 3, 4, 9}}] ;[o] 1 -2 -2 -2 -2 2 6 4 4 4 -3 -6 -6 -10 -10 1 2 3 6 1 1 2 3 4 9 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, -2, 1, 0, 0}, {0, 1, -2, 0, 0}, {-2, 0, 1, 1, 0}, {1, 0, 0, -2, -1}, {0, 0, 0, 1, 1}}] ;[o] 2 -2 1 0 0 0 1 -2 0 0 -2 0 1 1 0 1 0 0 -2 -1 0 0 0 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, 0, 0, 0, 0}, {0, 2, 0, 0, 0}, {0, 0, 3, 0, 0}, {0, 0, 0, 4, 0}, {0, 0, 0, 0, 5}}] ;[o] 2 0 0 0 0 0 2 0 0 0 0 0 3 0 0 0 0 0 4 0 0 0 0 0 5 :[font = input; initialization; preserveAspect; startGroup] *) z=Table[Z[i][x]/.DSolve[Z[i]'[x]==T[[i,i]]Z[i][x],Z[i][x],x] \ /.{C[1]->K[i]},{i,5}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^(2*x)*K[1]}, {E^(2*x)*K[2]}, {E^(3*x)*K[3]}, {E^(4*x)*K[4]}, {E^(5*x)*K[5]}}] ;[o] 2 x E K[1] 2 x E K[2] 3 x E K[3] 4 x E K[4] 5 x E K[5] :[font = input; initialization; preserveAspect; startGroup] *) y=P.z (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2*E^(2*x)*K[1] - 2*E^(2*x)*K[2] + E^(3*x)*K[3]}, {E^(2*x)*K[2] - 2*E^(3*x)*K[3]}, {-2*E^(2*x)*K[1] + E^(3*x)*K[3] + E^(4*x)*K[4]}, {E^(2*x)*K[1] - 2*E^(4*x)*K[4] - E^(5*x)*K[5]}, {E^(4*x)*K[4] + E^(5*x)*K[5]}}] ;[o] 2 x 2 x 3 x 2 E K[1] - 2 E K[2] + E K[3] 2 x 3 x E K[2] - 2 E K[3] 2 x 3 x 4 x -2 E K[1] + E K[3] + E K[4] 2 x 4 x 5 x E K[1] - 2 E K[4] - E K[5] 4 x 5 x E K[4] + E K[5] :[font = input; initialization; preserveAspect; startGroup] *) D[y,x]-M.y//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0}, {0}, {0}, {0}, {0}}] ;[o] 0 0 0 0 0 :[font = input; initialization; preserveAspect] *) Exercise 4 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{2,0,-1,-1,-1}, \ {3,8,8,7,7}, \ {-3,-6,-6,-7,-8}, \ {1,2,3,5,4}, \ {0,0,0,0,2}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, 0, -1, -1, -1}, {3, 8, 8, 7, 7}, {-3, -6, -6, -7, -8}, {1, 2, 3, 5, 4}, {0, 0, 0, 0, 2}}] ;[o] 2 0 -1 -1 -1 3 8 8 7 7 -3 -6 -6 -7 -8 1 2 3 5 4 0 0 0 0 2 :[font = input; initialization; preserveAspect; startGroup] *) EV=Eigensystem[M][[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-3, 5, -5, 2, 0}, {-2, 1, 0, 0, 0}, {0, 0, 0, 0, 0}, {-1, -1, 1, 0, 0}, {0, 0, 0, 0, 0}}] ;[o] -3 5 -5 2 0 -2 1 0 0 0 0 0 0 0 0 -1 -1 1 0 0 0 0 0 0 0 :[font = input; initialization; preserveAspect] *) Since we have only 3 linearly independent, nonzero eigenvectors, M is not diagonalizable. (* :[font = input; initialization; preserveAspect; startGroup] *) NullSpace[EV] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 0, 0, 0, 1}, {1, 2, 3, 4, 0}}] ;[o] 0 0 0 0 1 1 2 3 4 0 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Join[{EV[[1]]},{EV[[2]]},{EV[[4]]},%]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-3, -2, -1, 0, 1}, {5, 1, -1, 0, 2}, {-5, 0, 1, 0, 3}, {2, 0, 0, 0, 4}, {0, 0, 0, 1, 0}}] ;[o] -3 -2 -1 0 1 5 1 -1 0 2 -5 0 1 0 3 2 0 0 0 4 0 0 0 1 0 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, 0, 0, 5/3, 11}, {0, 2, 0, -11/6, -5}, {0, 0, 3, -1/6, -15}, {0, 0, 0, 2, 0}, {0, 0, 0, 1/6, 3}}] ;[o] 5 - 1 0 0 3 11 11 -(--) 0 2 0 6 -5 1 -(-) 0 0 3 6 -15 0 0 0 2 0 1 - 0 0 0 6 3 :[font = input; initialization; preserveAspect; startGroup] *) <K[6-i]},{i,5}] z//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^x*K[1] + E^(2*x)*K[4] + (11*E^(3*x)*K[5])/2}, {E^(2*x)*K[2] + 6*E^(2*x)*x*K[4] - 5*E^(3*x)*K[5]}, {E^(3*x)*K[3] + 14*E^(2*x)*K[4] - 15*E^(3*x)*x*K[5]}, {E^(2*x)*K[4]}, {E^(3*x)*K[5]}}] ;[o] 3 x x 2 x 11 E K[5] E K[1] + E K[4] + ------------ 2 2 x 2 x 3 x E K[2] + 6 E x K[4] - 5 E K[5] 3 x 2 x 3 x E K[3] + 14 E K[4] - 15 E x K[5] 2 x E K[4] 3 x E K[5] :[font = input; initialization; preserveAspect; startGroup] *) y=P.z//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-3*E^x*K[1] - 2*E^(2*x)*K[2] - E^(3*x)*K[3] - 16*E^(2*x)*K[4] - 12*E^(2*x)*x*K[4] - (11*E^(3*x)*K[5])/2 + 15*E^(3*x)*x*K[5]}, {5*E^x*K[1] + E^(2*x)*K[2] - E^(3*x)*K[3] - 7*E^(2*x)*K[4] + 6*E^(2*x)*x*K[4] + (49*E^(3*x)*K[5])/2 + 15*E^(3*x)*x*K[5]}, {-5*E^x*K[1] + E^(3*x)*K[3] + 12*E^(2*x)*K[4] - (49*E^(3*x)*K[5])/2 - 15*E^(3*x)*x*K[5]}, {2*E^x*K[1] + 6*E^(2*x)*K[4] + 15*E^(3*x)*K[5]}, {-6*E^(2*x)*K[4]}}] ;[o] x 2 x 3 x 2 x -3 E K[1] - 2 E K[2] - E K[3] - 16 E K[4] - 3 x 2 x 11 E K[5] 3 x 12 E x K[4] - ------------ + 15 E x K[5] 2 x 2 x 3 x 2 x 5 E K[1] + E K[2] - E K[3] - 7 E K[4] + 3 x 2 x 49 E K[5] 3 x 6 E x K[4] + ------------ + 15 E x K[5] 2 3 x x 3 x 2 x 49 E K[5] -5 E K[1] + E K[3] + 12 E K[4] - ------------ - 2 3 x 15 E x K[5] x 2 x 3 x 2 E K[1] + 6 E K[4] + 15 E K[5] 2 x -6 E K[4] :[font = input; initialization; preserveAspect; startGroup] *) D[y,x]-M.y//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0}, {0}, {0}, {0}, {0}}] ;[o] 0 0 0 0 0 :[font = input; initialization; preserveAspect] *) Exercise 5 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{-205,-409,-613,-817,-1021,-1225}, \ {494,986,1479,1972,2465,2958}, \ {-662,-1323,-1986,-2648,-3310,-3972},\ {539,1078,1618,2156,2695,3234}, \ {-272,-544,-816,-1087,-1360,-1632}, \ {70,140,210,280,351,421}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-205, -409, -613, -817, -1021, -1225}, {494, 986, 1479, 1972, 2465, 2958}, {-662, -1323, -1986, -2648, -3310, -3972}, {539, 1078, 1618, 2156, 2695, 3234}, {-272, -544, -816, -1087, -1360, -1632}, {70, 140, 210, 280, 351, 421}}] ;[o] -205 -409 -613 -817 -1021 -1225 494 986 1479 1972 2465 2958 -662 -1323 -1986 -2648 -3310 -3972 539 1078 1618 2156 2695 3234 -272 -544 -816 -1087 -1360 -1632 70 140 210 280 351 421 :[font = input; initialization; preserveAspect; startGroup] *) EV=Eigensystem[M][[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-168, 325, -337, 202, -70, 12}, {0, 0, 0, 0, 0, 0}, {-93, 200, -231, 154, -59, 11}, {0, 0, 0, 0, 0, 0}, {-64, 143, -173, 122, -50, 10}, {0, 0, 0, 0, 0, 0}}] ;[o] -168 325 -337 202 -70 12 0 0 0 0 0 0 -93 200 -231 154 -59 11 0 0 0 0 0 0 -64 143 -173 122 -50 10 0 0 0 0 0 0 :[font = input; initialization; preserveAspect; startGroup] *) NullSpace[EV] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{3590, 3937, 2137, 0, 0, 3647}, {-9717, -11218, -6732, 0, 3647, 0}, {7824, 10100, 8026, 3647, 0, 0}}] ;[o] 3590 3937 2137 0 0 3647 -9717 -11218 -6732 0 3647 0 7824 10100 8026 3647 0 0 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Join[{EV[[1]]},{EV[[3]]},{EV[[5]]},%]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-168, -93, -64, 3590, -9717, 7824}, {325, 200, 143, 3937, -11218, 10100}, {-337, -231, -173, 2137, -6732, 8026}, {202, 154, 122, 0, 0, 3647}, {-70, -59, -50, 0, 3647, 0}, {12, 11, 10, 3647, 0, 0}}] ;[o] -168 -93 -64 3590 -9717 7824 325 200 143 3937 -11218 10100 -337 -231 -173 2137 -6732 8026 202 154 122 0 0 3647 -70 -59 -50 0 3647 0 12 11 10 3647 0 0 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P; T//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{1, 0, 0, 123731863945233/1309474756, -26854095075623/327368689, 51979335296230/327368689}, {0, 2, 0, -478078118052553/654737378, 206378534111209/327368689, -401302318801220/327368689}, {0, 0, 3, 1234440253205609/1309474756, -265886302282338/327368689, 517934756801526/327368689}, {0, 0, 0, 84391125848213/1193913608783, -69607679841880/1193913608783, 139481166102100/1193913608783}, {0, 0, 0, -13607792540137/341118173938, 5698346761619/170559086969, -11244977904331/170559086969} , {0, 0, 0, -70981009009520/1193913608783, 58683893502254/1193913608783, -117116071526848/1193913608783}}] ;[o] 123731863945233 26854095075623 --------------- -(--------------) 1 0 0 1309474756 327368689 51979335296230 -------------- 327368689 478078118052553 206378534111209 -(---------------) --------------- 0 2 0 654737378 327368689 401302318801220 -(---------------) 327368689 1234440253205609 265886302282338 ---------------- -(---------------) 0 0 3 1309474756 327368689 517934756801526 --------------- 327368689 84391125848213 69607679841880 -------------- -(--------------) 0 0 0 1193913608783 1193913608783 139481166102100 --------------- 1193913608783 13607792540137 5698346761619 -(--------------) ------------- 0 0 0 341118173938 170559086969 11244977904331 -(--------------) 170559086969 70981009009520 58683893502254 -(--------------) -------------- 0 0 0 1193913608783 1193913608783 117116071526848 -(---------------) 1193913608783 :[font = input; initialization; preserveAspect; startGroup] *) B=Array[T[[3+#1,3+#2]]&,{3,3}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{84391125848213/1193913608783, -69607679841880/1193913608783, 139481166102100/1193913608783}, {-13607792540137/341118173938, 5698346761619/170559086969, -11244977904331/170559086969} , {-70981009009520/1193913608783, 58683893502254/1193913608783, -117116071526848/1193913608783}}] ;[o] 84391125848213 69607679841880 139481166102100 -------------- -(--------------) --------------- 1193913608783 1193913608783 1193913608783 13607792540137 5698346761619 11244977904331 -(--------------) ------------- -(--------------) 341118173938 170559086969 170559086969 70981009009520 58683893502254 117116071526848 -(--------------) -------------- -(---------------) 1193913608783 1193913608783 1193913608783 :[font = input; initialization; preserveAspect; startGroup] *) EVB=Eigensystem[B][[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-199614164/233563639, 458868527/467127278, 1}, {-50535780/48811633, 38274553/48811633, 1}, {-14389730/13219447, 19567917/26438894, 1}}] ;[o] 199614164 458868527 -(---------) --------- 233563639 467127278 1 50535780 38274553 -(--------) -------- 48811633 48811633 1 14389730 19567917 -(--------) -------- 13219447 26438894 1 :[font = input; initialization; preserveAspect; startGroup] *) PB=Transpose[EVB] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-199614164/233563639, -50535780/48811633, -14389730/13219447}, {458868527/467127278, 38274553/48811633, 19567917/26438894}, {1, 1, 1}}] ;[o] 199614164 50535780 14389730 -(---------) -(--------) -(--------) 233563639 48811633 13219447 458868527 38274553 19567917 --------- -------- -------- 467127278 48811633 26438894 1 1 1 :[font = input; initialization; preserveAspect; startGroup] *) Table[If[i<4 || j<4,IdentityMatrix[6][[i,j]],PB[[i-3,j-3]]], \ {i,6},{j,6}]; %//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{1, 0, 0, 0, 0, 0}, {0, 1, 0, 0, 0, 0}, {0, 0, 1, 0, 0, 0}, {0, 0, 0, -199614164/233563639, -50535780/48811633, -14389730/13219447}, {0, 0, 0, 458868527/467127278, 38274553/48811633, 19567917/26438894}, {0, 0, 0, 1, 1, 1}}] ;[o] 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 199614164 50535780 14389730 -(---------) -(--------) -(--------) 0 0 0 233563639 48811633 13219447 458868527 38274553 19567917 --------- -------- -------- 0 0 0 467127278 48811633 26438894 0 0 0 1 1 1 :[font = input; initialization; preserveAspect; startGroup] *) P=P.%%; P//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{-168, -93, -64, -2237251351307/467127278, -171435065109/48811633, -86601804233/26438894}, {325, 200, 143, -1000681777711/233563639, -135325808114/48811633, -1134220647/455843}, {-337, -231, -173, -96545163736/233563639, 26102913802/48811633, 9482819990/13219447}, {202, 154, 122, 3647, 3647, 3647}, {-70, -59, -50, 1673493517969/467127278, 139587294791/48811633, 71364193299/26438894}, {12, 11, 10, -727992856108/233563639, -184303989660/48811633, -52479345310/13219447}}] ;[o] 2237251351307 171435065109 -(-------------) -(------------) -168 -93 -64 467127278 48811633 86601804233 -(-----------) 26438894 1000681777711 135325808114 -(-------------) -(------------) 325 200 143 233563639 48811633 1134220647 -(----------) 455843 96545163736 26102913802 -(-----------) ----------- -337 -231 -173 233563639 48811633 9482819990 ---------- 13219447 202 154 122 3647 3647 3647 1673493517969 139587294791 ------------- ------------ -70 -59 -50 467127278 48811633 71364193299 ----------- 26438894 727992856108 184303989660 -(------------) -(------------) 12 11 10 233563639 48811633 52479345310 -(-----------) 13219447 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P; T//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{1, 0, 0, -1193913608783/467127278, -12654236602/3754741, -63287397572/13219447}, {0, 2, 0, 8163633441075/467127278, 1193913608783/48811633, 940296385567/26438894}, {0, 0, 3, -4996327439362/233563639, -1500718862349/48811633, -1193913608783/26438894}, {0, 0, 0, 1, 0, 0}, {0, 0, 0, 0, 2, 0}, {0, 0, 0, 0, 0, 3}}] ;[o] 1193913608783 12654236602 -(-------------) -(-----------) 1 0 0 467127278 3754741 63287397572 -(-----------) 13219447 8163633441075 1193913608783 ------------- ------------- 0 2 0 467127278 48811633 940296385567 ------------ 26438894 4996327439362 1500718862349 -(-------------) -(-------------) 0 0 3 233563639 48811633 1193913608783 -(-------------) 26438894 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 3 :[font = input; initialization; preserveAspect; startGroup] *) z=Array[0&,6]; Do[z[[7-i]]=Z[7-i][x]/.DSolve[Z[7-i]'[x]==T[[7-i,7-i]]Z[7-i][x] \ +Sum[T[[7-i,j]]z[[j,1]],{j,8-i,6}], \ Z[7-i][x],x]/.{C[1]->K[7-i]},{i,6}] z//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^x*K[1] - (1193913608783*E^x*x*K[4])/ 467127278 - (12654236602*E^(2*x)*K[5])/3754741 - (31643698786*E^(3*x)*K[6])/13219447}, {E^(2*x)*K[2] - (8163633441075*E^x*K[4])/467127278 + (1193913608783*E^(2*x)*x*K[5])/48811633 + (940296385567*E^(3*x)*K[6])/26438894}, {E^(3*x)*K[3] + (2498163719681*E^x*K[4])/233563639 + (1500718862349*E^(2*x)*K[5])/48811633 - (1193913608783*E^(3*x)*x*K[6])/26438894}, {E^x*K[4]}, {E^(2*x)*K[5]}, {E^(3*x)*K[6]}}] ;[o] x 2 x x 1193913608783 E x K[4] 12654236602 E K[5] E K[1] - ----------------------- - --------------------- - 467127278 3754741 3 x 31643698786 E K[6] --------------------- 13219447 x 2 x 8163633441075 E K[4] E K[2] - --------------------- + 467127278 2 x 3 x 1193913608783 E x K[5] 940296385567 E K[6] ------------------------- + ---------------------- 48811633 26438894 x 3 x 2498163719681 E K[4] E K[3] + --------------------- + 233563639 2 x 3 x 1500718862349 E K[5] 1193913608783 E x K[6] ----------------------- - ------------------------- 48811633 26438894 x E K[4] 2 x E K[5] 3 x E K[6] :[font = input; initialization; preserveAspect; startGroup] *) y=P.z//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-168*E^x*K[1] - 93*E^(2*x)*K[2] - 64*E^(3*x)*K[3] + (218607851274750*E^x*K[4])/ 233563639 + (100288743137772*E^x*x*K[4])/233563639 - (68580589516677*E^(2*x)*K[5])/48811633 - (111033965616819*E^(2*x)*x*K[5])/48811633 - (38450941434934*E^(3*x)*K[6])/13219447 + (38205235481056*E^(3*x)*x*K[6])/13219447}, {325*E^x*K[1] + 200*E^(2*x)*K[2] + 143*E^(3*x)*K[3] - (460126613970828*E^x*K[4])/233563639 - (388021922854475*E^x*x*K[4])/467127278 + (161003321864343*E^(2*x)*K[5])/48811633 + (238782721756600*E^(2*x)*x*K[5])/48811633 + (83712544052487*E^(3*x)*K[6])/13219447 - (170729646055969*E^(3*x)*x*K[6])/26438894}, {-337*E^x*K[1] - 231*E^(2*x)*K[2] - 173*E^(3*x)*K[3] + (1021241587551227*E^x*K[4])/467127278 + (402348886159871*E^x*x*K[4])/467127278 - (204160049719213*E^(2*x)*K[5])/48811633 - (275794043628873*E^(2*x)*x*K[5])/48811633 - (4554922010331*E^(3*x)*K[6])/614858 + (206547054319459*E^(3*x)*x*K[6])/26438894}, {202*E^x*K[1] + 154*E^(2*x)*K[2] + 122*E^(3*x)*K[3] - (322971994570260*E^x*K[4])/233563639 - (120585274487083*E^x*x*K[4])/233563639 + (150035691915277*E^(2*x)*K[5])/48811633 + (183862695752582*E^(2*x)*x*K[5])/48811633 + (66059005857096*E^(3*x)*K[6])/13219447 - (72828730135763*E^(3*x)*x*K[6])/13219447}, {-70*E^x*K[1] - 59*E^(2*x)*K[2] - 50*E^(3*x)*K[3] + (116755747286647*E^x*K[4])/233563639 + (41786976307405*E^x*x*K[4])/233563639 - (63381000514839*E^(2*x)*K[5])/48811633 - (70440902918197*E^(2*x)*x*K[5])/48811633 - (25488002362557*E^(3*x)*K[6])/13219447 + (29847840219575*E^(3*x)*x*K[6])/13219447}, {12*E^x*K[1] + 11*E^(2*x)*K[2] + 10*E^(3*x)*K[3] - (41292679170421*E^x*K[4])/467127278 - (7163481652698*E^x*x*K[4])/233563639 + (988371055686*E^(2*x)*K[5])/3754741 + (13133049696613*E^(2*x)*x*K[5])/48811633 + (9478852779753*E^(3*x)*K[6])/26438894 - (5969568043915*E^(3*x)*x*K[6])/13219447}}] ;[o] x 2 x 3 x -168 E K[1] - 93 E K[2] - 64 E K[3] + x x 218607851274750 E K[4] 100288743137772 E x K[4] ----------------------- + ------------------------- - 233563639 233563639 2 x 2 x 68580589516677 E K[5] 111033965616819 E x K[5] ------------------------ - --------------------------- - 48811633 48811633 3 x 3 x 38450941434934 E K[6] 38205235481056 E x K[6] ------------------------ + -------------------------- 13219447 13219447 x 2 x 3 x 325 E K[1] + 200 E K[2] + 143 E K[3] - x x 460126613970828 E K[4] 388021922854475 E x K[4] ----------------------- - ------------------------- + 233563639 467127278 2 x 2 x 161003321864343 E K[5] 238782721756600 E x K[5] ------------------------- + --------------------------- + 48811633 48811633 3 x 3 x 83712544052487 E K[6] 170729646055969 E x K[6] ------------------------ - --------------------------- 13219447 26438894 x 2 x 3 x -337 E K[1] - 231 E K[2] - 173 E K[3] + x x 1021241587551227 E K[4] 402348886159871 E x K[4] ------------------------ + ------------------------- - 467127278 467127278 2 x 2 x 204160049719213 E K[5] 275794043628873 E x K[5] ------------------------- - --------------------------- - 48811633 48811633 3 x 3 x 4554922010331 E K[6] 206547054319459 E x K[6] ----------------------- + --------------------------- 614858 26438894 x 2 x 3 x 202 E K[1] + 154 E K[2] + 122 E K[3] - x x 322971994570260 E K[4] 120585274487083 E x K[4] ----------------------- - ------------------------- + 233563639 233563639 2 x 2 x 150035691915277 E K[5] 183862695752582 E x K[5] ------------------------- + --------------------------- + 48811633 48811633 3 x 3 x 66059005857096 E K[6] 72828730135763 E x K[6] ------------------------ - -------------------------- 13219447 13219447 x 2 x 3 x -70 E K[1] - 59 E K[2] - 50 E K[3] + x x 116755747286647 E K[4] 41786976307405 E x K[4] ----------------------- + ------------------------ - 233563639 233563639 2 x 2 x 63381000514839 E K[5] 70440902918197 E x K[5] ------------------------ - -------------------------- - 48811633 48811633 3 x 3 x 25488002362557 E K[6] 29847840219575 E x K[6] ------------------------ + -------------------------- 13219447 13219447 x 2 x 3 x 12 E K[1] + 11 E K[2] + 10 E K[3] - x x 41292679170421 E K[4] 7163481652698 E x K[4] ---------------------- - ----------------------- + 467127278 233563639 2 x 2 x 988371055686 E K[5] 13133049696613 E x K[5] ---------------------- + -------------------------- + 3754741 48811633 3 x 3 x 9478852779753 E K[6] 5969568043915 E x K[6] ----------------------- - ------------------------- 26438894 13219447 :[font = input; initialization; preserveAspect; startGroup] *) D[y,x]-M.y//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0}, {0}, {0}, {0}, {0}, {0}}] ;[o] 0 0 0 0 0 0 :[font = input; initialization; preserveAspect] *) Problems on Differential Equations (* :[font = input; initialization; preserveAspect] *) Problem 1 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{0,1}, \ {-2,-1}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 1}, {-2, -1}}] ;[o] 0 1 -2 -1 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{I/4*(I + 7^(1/2)), -I/4*(-I + 7^(1/2))}, {1, 1}}] ;[o] I -I - (I + Sqrt[7]) -- (-I + Sqrt[7]) 4 4 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P//Together (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-I/2*(-I + 7^(1/2)), 0}, {0, I/2*(I + 7^(1/2))}}] ;[o] -I -- (-I + Sqrt[7]) 2 0 I - (I + Sqrt[7]) 0 2 :[font = input; initialization; preserveAspect; startGroup] *) k={0,E^x} (* :[font = output; output; inactive; preserveAspect; endGroup] {0, E^x} ;[o] x {0, E } :[font = input; initialization; preserveAspect; startGroup] *) IPk=Inverse[P].k//Together (* :[font = output; output; inactive; preserveAspect; endGroup] {((-I + 7^(1/2))*E^x)/(2*7^(1/2)), ((I + 7^(1/2))*E^x)/(2*7^(1/2))} ;[o] x x (-I + Sqrt[7]) E (I + Sqrt[7]) E {-----------------, ----------------} 2 Sqrt[7] 2 Sqrt[7] :[font = input; initialization; preserveAspect; startGroup] *) z=Table[Z[i][x]/.DSolve[Z[i]'[x]==T[[i,i]]Z[i][x]+IPk[[i]], \ Z[i][x],x]/.{C[1]->K[i]},{i,2}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-((7*I + 7^(1/2))*E^x)/(7*(-3*I + 7^(1/2))) + E^((-1/2 - I/2*7^(1/2))*x)*K[1]}, {-((-7*I + 7^(1/2))*E^x)/(7*(3*I + 7^(1/2))) + E^((-1/2 + I/2*7^(1/2))*x)*K[2]}}] ;[o] x -((7 I + Sqrt[7]) E ) (-(1/2) - I/2 Sqrt[7]) x --------------------- + E K[1] 7 (-3 I + Sqrt[7]) x -((-7 I + Sqrt[7]) E ) (-(1/2) + I/2 Sqrt[7]) x ---------------------- + E K[2] 7 (3 I + Sqrt[7]) :[font = input; initialization; preserveAspect; startGroup] *) u=P.z//Together//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{(E^x - E^((-1/2 - I/2*7^(1/2))*x)*K[1] + I*7^(1/2)*E^((-1/2 - I/2*7^(1/2))*x)*K[1] - E^(I/2*(I + 7^(1/2))*x)*K[2] - I*7^(1/2)*E^(I/2*(I + 7^(1/2))*x)*K[2])/4}, {E^x/4 + E^((-1/2 - I/2*7^(1/2))*x)*K[1] + E^(I/2*(I + 7^(1/2))*x)*K[2]}}] ;[o] x (-(1/2) - I/2 Sqrt[7]) x (E - E K[1] + (-(1/2) - I/2 Sqrt[7]) x I Sqrt[7] E K[1] - I/2 (I + Sqrt[7]) x E K[2] - I/2 (I + Sqrt[7]) x I Sqrt[7] E K[2]) / 4 x E (-(1/2) - I/2 Sqrt[7]) x -- + E K[1] + 4 I/2 (I + Sqrt[7]) x E K[2] :[font = input; initialization; preserveAspect; startGroup] *) yRe=Re[u[[1]]] (* :[font = output; output; inactive; preserveAspect; endGroup] {Re[(E^x - E^((-1/2 - I/2*7^(1/2))*x)*K[1] + I*7^(1/2)*E^((-1/2 - I/2*7^(1/2))*x)*K[1] - E^(I/2*(I + 7^(1/2))*x)*K[2] - I*7^(1/2)*E^(I/2*(I + 7^(1/2))*x)*K[2])/4]} ;[o] x (-(1/2) - I/2 Sqrt[7]) x {Re[(E - E K[1] + (-(1/2) - I/2 Sqrt[7]) x I Sqrt[7] E K[1] - I/2 (I + Sqrt[7]) x E K[2] - I/2 (I + Sqrt[7]) x I Sqrt[7] E K[2]) / 4]} :[font = input; initialization; preserveAspect] *) Mathematica does not know if the constants are real (* :[font = input; initialization; preserveAspect; startGroup] *) yRe=(E^x-E^(-x/2)Cos[Sqrt[7]x/2](K[1]-K[2])+ \ Sqrt[7]E^(-x/2)Sin[Sqrt[7]x/2](K[1]+K[2]))/4 (* :[font = output; output; inactive; preserveAspect; endGroup] (E^x - (Cos[(7^(1/2)*x)/2]*(K[1] - K[2]))/E^(x/2) + (7^(1/2)*(K[1] + K[2])*Sin[(7^(1/2)*x)/2])/E^(x/2))/4 ;[o] Sqrt[7] x Cos[---------] (K[1] - K[2]) x 2 (E - ---------------------------- + x/2 E Sqrt[7] x Sqrt[7] (K[1] + K[2]) Sin[---------] 2 ------------------------------------) / 4 x/2 E :[font = input; initialization; preserveAspect] *) Solution check: (* :[font = input; initialization; preserveAspect; startGroup] *) D[D[yRe,x],x]+D[yRe,x]+2yRe//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] E^x ;[o] x E :[font = input; initialization; preserveAspect] *) Problem 2 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{1/75,-1/150}, \ {1/75,-1/300}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1/75, -1/150}, {1/75, -1/300}}] ;[o] 1 1 -- -(---) 75 150 1 1 -- -(---) 75 300 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-I/8*(5*I + 7^(1/2)), I/8*(-5*I + 7^(1/2))}, {1, 1}}] ;[o] -I I -- (5 I + Sqrt[7]) - (-5 I + Sqrt[7]) 8 8 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P//Together (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{(3 - I*7^(1/2))/600, 0}, {0, (3 + I*7^(1/2))/600}}] ;[o] 3 - I Sqrt[7] ------------- 600 0 3 + I Sqrt[7] ------------- 0 600 :[font = input; initialization; preserveAspect; startGroup] *) Clear[K] z=Table[Z[i][t]/.DSolve[Z[i]'[t]==T[[i,i]]Z[i][t],Z[i][t],t] \ /.{C[1]->K[i]},{i,2}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^((1/200 - I/600*7^(1/2))*t)*K[1]}, {E^((1/200 + I/600*7^(1/2))*t)*K[2]}}] ;[o] (1/200 - I/600 Sqrt[7]) t E K[1] (1/200 + I/600 Sqrt[7]) t E K[2] :[font = input; initialization; preserveAspect; startGroup] *) r=(P.z)[[1]] (* :[font = output; output; inactive; preserveAspect; endGroup] {-I/8*(5*I + 7^(1/2))*E^((1/200 - I/600*7^(1/2))*t)*K[1] + I/8*(-5*I + 7^(1/2))*E^((1/200 + I/600*7^(1/2))*t)*K[2]} ;[o] -I (1/200 - I/600 Sqrt[7]) t {-- (5 I + Sqrt[7]) E K[1] + 8 I (1/200 + I/600 Sqrt[7]) t - (-5 I + Sqrt[7]) E K[2]} 8 :[font = input; initialization; preserveAspect; startGroup] *) f=(P.z)[[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] {E^((1/200 - I/600*7^(1/2))*t)*K[1] + E^((1/200 + I/600*7^(1/2))*t)*K[2]} ;[o] (1/200 - I/600 Sqrt[7]) t {E K[1] + (1/200 + I/600 Sqrt[7]) t E K[2]} :[font = input; initialization; preserveAspect] *) a) (* :[font = input; initialization; preserveAspect; startGroup] *) Solve[(r/.{t->0})-1000==0,K[2]]//Expand; Solve[(f/.{t->0}/.%)-1000==0,K[1]]//Expand; Re[r/.{t->{10,20,100}}/.%%/.%//N] (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{1067.764700186698003, 1137.667110988617783, 1756.977404441146643}}}} ;[o] {{{{1067.76, 1137.67, 1756.98}}}} :[font = input; initialization; preserveAspect; startGroup] *) Re[f/.{t->{10,20,100}}/.%%%/.%%//N] (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{1102.795714846362742, 1211.249700731157621, 2288.913256528842839}}}} ;[o] {{{{1102.8, 1211.25, 2288.91}}}} :[font = input; initialization; preserveAspect] *) b) (* :[font = input; initialization; preserveAspect; startGroup] *) Solve[(r/.{t->0})-2000==0,K[2]]//Expand; Solve[(f/.{t->0}/.%)-1000==0,K[1]]//Expand; Re[r/.{t->{10,20,100}}/.%%/.%//N] (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{2205.591429692725483, 2422.499401462315243, 4577.826513057685679}}}} ;[o] {{{{2205.59, 2422.5, 4577.83}}}} :[font = input; initialization; preserveAspect; startGroup] *) Re[f/.{t->{10,20,100}}/.%%%/.%%//N] (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{1242.919773485021695, 1505.580059701316973, 4416.656664879627626}}}} ;[o] {{{{1242.92, 1505.58, 4416.66}}}} :[font = input; initialization; preserveAspect] *) Problem 3 (* :[font = input; initialization; preserveAspect] *) Since both w1/g and w2/g are equal to 1, we will just skip writing them. (* :[font = input; initialization; preserveAspect; startGroup] *) k1=12; k2=10; k3=12; M={{0,1,0,0}, \ {-k1-k2,0,k2,0},\ {0,0,0,1}, \ {k2,0,-k2-k3,0}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 1, 0, 0}, {-22, 0, 10, 0}, {0, 0, 0, 1}, {10, 0, -22, 0}}] ;[o] 0 1 0 0 -22 0 10 0 0 0 0 1 10 0 -22 0 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]]//Together (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-I/4/2^(1/2), I/4/2^(1/2), I/2/3^(1/2), -I/2/3^(1/2)}, {-1, -1, 1, 1}, {I/4/2^(1/2), -I/4/2^(1/2), I/2/3^(1/2), -I/2/3^(1/2)}, {1, 1, 1, 1}}] ;[o] -I I I -I -- - - -- 4 4 2 2 ------- ------- ------- ------- Sqrt[2] Sqrt[2] Sqrt[3] Sqrt[3] -1 -1 1 1 I -I I -I - -- - -- 4 4 2 2 ------- ------- ------- ------- Sqrt[2] Sqrt[2] Sqrt[3] Sqrt[3] 1 1 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-4*I*2^(1/2), 0, 0, 0}, {0, 4*I*2^(1/2), 0, 0}, {0, 0, -2*I*3^(1/2), 0}, {0, 0, 0, 2*I*3^(1/2)}}] ;[o] -4 I Sqrt[2] 0 0 0 0 4 I Sqrt[2] 0 0 0 0 -2 I Sqrt[3] 0 0 0 0 2 I Sqrt[3] :[font = input; initialization; preserveAspect; startGroup] *) Clear[K] z=Table[Z[i][t]/.DSolve[Z[i]'[t]==T[[i,i]]Z[i][t],Z[i][t],t] \ /.{C[1]->K[i]},{i,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^(-4*I*2^(1/2)*t)*K[1]}, {E^(4*I*2^(1/2)*t)*K[2]}, {E^(-2*I*3^(1/2)*t)*K[3]}, {E^(2*I*3^(1/2)*t)*K[4]}}] ;[o] -4 I Sqrt[2] t E K[1] 4 I Sqrt[2] t E K[2] -2 I Sqrt[3] t E K[3] 2 I Sqrt[3] t E K[4] :[font = input; initialization; preserveAspect; startGroup] *) u=P.z (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{(-I/4*E^(-4*I*2^(1/2)*t)*K[1])/2^(1/2) + (I/4*E^(4*I*2^(1/2)*t)*K[2])/2^(1/2) + (I/2*E^(-2*I*3^(1/2)*t)*K[3])/3^(1/2) - (I/2*E^(2*I*3^(1/2)*t)*K[4])/3^(1/2)}, {-(E^(-4*I*2^(1/2)*t)*K[1]) - E^(4*I*2^(1/2)*t)*K[2] + E^(-2*I*3^(1/2)*t)*K[3] + E^(2*I*3^(1/2)*t)*K[4]}, {(I/4*E^(-4*I*2^(1/2)*t)*K[1])/2^(1/2) - (I/4*E^(4*I*2^(1/2)*t)*K[2])/2^(1/2) + (I/2*E^(-2*I*3^(1/2)*t)*K[3])/3^(1/2) - (I/2*E^(2*I*3^(1/2)*t)*K[4])/3^(1/2)}, {E^(-4*I*2^(1/2)*t)*K[1] + E^(4*I*2^(1/2)*t)*K[2] + E^(-2*I*3^(1/2)*t)*K[3] + E^(2*I*3^(1/2)*t)*K[4]}}] ;[o] -I -4 I Sqrt[2] t I 4 I Sqrt[2] t -- E K[1] - E K[2] 4 4 ----------------------- + --------------------- + Sqrt[2] Sqrt[2] I -2 I Sqrt[3] t I 2 I Sqrt[3] t - E K[3] - E K[4] 2 2 ---------------------- - --------------------- Sqrt[3] Sqrt[3] -4 I Sqrt[2] t 4 I Sqrt[2] t -(E K[1]) - E K[2] + -2 I Sqrt[3] t 2 I Sqrt[3] t E K[3] + E K[4] I -4 I Sqrt[2] t I 4 I Sqrt[2] t - E K[1] - E K[2] 4 4 ---------------------- - --------------------- + Sqrt[2] Sqrt[2] I -2 I Sqrt[3] t I 2 I Sqrt[3] t - E K[3] - E K[4] 2 2 ---------------------- - --------------------- Sqrt[3] Sqrt[3] -4 I Sqrt[2] t 4 I Sqrt[2] t E K[1] + E K[2] + -2 I Sqrt[3] t 2 I Sqrt[3] t E K[3] + E K[4] :[font = input; initialization; preserveAspect; startGroup] *) Clear[y] Solve[(u[[1]]/.{t->0})-10==0,K[1]]//Expand; Solve[(u[[2]]/.{t->0}/.%)==0,K[2]]//Expand; Solve[(u[[3]]/.{t->0}/.%%/.%)-12==0,K[3]]//Expand; Solve[(u[[4]]/.{t->0}/.%%%/.%%/.%)==0,K[4]]//Expand; y[1]=u[[1]]/.%%%%/.%%%/.%%/.%//ComplexExpand (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{{-Cos[4*2^(1/2)*t] + 11*Cos[2*3^(1/2)*t]}}}}} ;[o] {{{{{-Cos[4 Sqrt[2] t] + 11 Cos[2 Sqrt[3] t]}}}}} :[font = input; initialization; preserveAspect; startGroup] *) y[2]=u[[3]]/.%%%%%/.%%%%/.%%%/.%%//ComplexExpand (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{{Cos[4*2^(1/2)*t] + 11*Cos[2*3^(1/2)*t]}}}}} ;[o] {{{{{Cos[4 Sqrt[2] t] + 11 Cos[2 Sqrt[3] t]}}}}} :[font = input; initialization; preserveAspect] *) Exercises on the Matrix Exponential Function (* :[font = input; initialization; preserveAspect] *) Exercise 1 (* :[font = input; initialization; preserveAspect; startGroup] *) J3={{2,1,0}, \ {0,2,1}, \ {0,0,2}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, 1, 0}, {0, 2, 1}, {0, 0, 2}}] ;[o] 2 1 0 0 2 1 0 0 2 :[font = input; initialization; preserveAspect; startGroup] *) MatrixExp[J3 t] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{E^(2*t), E^(2*t)*t, (E^(2*t)*t^2)/2}, {0, E^(2*t), E^(2*t)*t}, {0, 0, E^(2*t)}}] ;[o] 2 t 2 E t 2 t 2 t ------- E E t 2 2 t 2 t 0 E E t 2 t 0 0 E :[font = input; initialization; preserveAspect] *) Exercise 2 (* :[font = input; initialization; preserveAspect; startGroup] *) A=Array[1&,{4,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}, {1, 1, 1, 1}}] ;[o] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 :[font = input; initialization; preserveAspect; startGroup] *) MatrixExp[A t] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{3/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4}, {-1/4 + E^(4*t)/4, 3/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4}, {-1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, 3/4 + E^(4*t)/4, -1/4 + E^(4*t)/4}, {-1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, -1/4 + E^(4*t)/4, 3/4 + E^(4*t)/4}}] ;[o] 4 t 4 t 4 t 4 t 3 E 1 E 1 E 1 E - + ---- -(-) + ---- -(-) + ---- -(-) + ---- 4 4 4 4 4 4 4 4 4 t 4 t 4 t 4 t 1 E 3 E 1 E 1 E -(-) + ---- - + ---- -(-) + ---- -(-) + ---- 4 4 4 4 4 4 4 4 4 t 4 t 4 t 4 t 1 E 1 E 3 E 1 E -(-) + ---- -(-) + ---- - + ---- -(-) + ---- 4 4 4 4 4 4 4 4 4 t 4 t 4 t 4 t 1 E 1 E 1 E 3 E -(-) + ---- -(-) + ---- -(-) + ---- - + ---- 4 4 4 4 4 4 4 4 :[font = input; initialization; preserveAspect] *) Exercise 3 (* :[font = input; initialization; preserveAspect; startGroup] *) A=Table[If[i>j,i,0],{i,4},{j,4}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 0, 0, 0}, {2, 0, 0, 0}, {3, 3, 0, 0}, {4, 4, 4, 0}}] ;[o] 0 0 0 0 2 0 0 0 3 3 0 0 4 4 4 0 :[font = input; initialization; preserveAspect; startGroup] *) MatrixExp[A t]//TableForm (* :[font = output; output; inactive; preserveAspect; endGroup] TableForm[{{1, 0, 0, 0}, {-5/3 + (20*t^2 + 24*t^3)/(12*t^2), 1, 0, 0}, {2/3 + (4*t + 20*t^2 + 12*t^3)/(4*t) - (20*t^2 + 24*t^3)/(12*t^2), -1 + (4*t + 12*t^2)/(4*t), 1, 0}, {4*t + 10*t^2 + 4*t^3, 4*t + 6*t^2, 4*t, 1}}] ;[o] 1 0 0 0 2 3 5 20 t + 24 t -(-) + ------------- 3 2 12 t 1 0 0 2 3 2 3 2 4 t + 20 t + 12 t 20 t + 24 t 2 - + ------------------- - ------------- 4 t + 12 t 3 4 t 2 -1 + ----------- 12 t 4 t 1 0 2 3 2 4 t + 10 t + 4 t 4 t + 6 t 4 t 1 :[font = input; initialization; preserveAspect] *) Exercise 4 (* :[font = input; initialization; preserveAspect] *) J[n_]:=Table[Which[j>i+1,0,j==i+1,1,j==i,2,j0},{1000,1000}]; K[1]=%[[1]] (* :[font = output; output; inactive; preserveAspect; endGroup] 1000 ;[o] 1000 :[font = input; initialization; preserveAspect; startGroup] *) K[2]=%%[[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] 1000 ;[o] 1000 :[font = input; initialization; preserveAspect; startGroup] *) Re[r/.{t->{10,20,100}}]//N (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1067.764700186698003, 1137.667110988617783, 1756.977404441146643}}] ;[o] 1067.76 1137.67 1756.98 :[font = input; initialization; preserveAspect; startGroup] *) Re[f/.{t->{10,20,100}}]//N (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1102.795714846362742, 1211.249700731157621, 2288.913256528842839}}] ;[o] 1102.8 1211.25 2288.91 :[font = input; initialization; preserveAspect] *) b) (* :[font = input; initialization; preserveAspect; startGroup] *) LinearSolve[A/.{t->0},{2000,1000}]; K[1]=%[[1]] (* :[font = output; output; inactive; preserveAspect; endGroup] 2000 ;[o] 2000 :[font = input; initialization; preserveAspect; startGroup] *) K[2]=%%[[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] 1000 ;[o] 1000 :[font = input; initialization; preserveAspect; startGroup] *) Re[r/.{t->{10,20,100}}]//N (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2205.591429692725483, 2422.499401462315243, 4577.826513057685678}}] ;[o] 2205.59 2422.5 4577.83 :[font = input; initialization; preserveAspect; startGroup] *) Re[f/.{t->{10,20,100}}]//N (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1242.919773485021695, 1505.580059701316973, 4416.656664879627625}}] ;[o] 1242.92 1505.58 4416.66 :[font = input; initialization; preserveAspect] *) Problem 4 (* :[font = input; initialization; preserveAspect; startGroup] *) k1=12; k2=10; k3=12; M={{0,1,0,0}, \ {-k1-k2,0,k2,0},\ {0,0,0,1}, \ {k2,0,-k2-k3,0}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 1, 0, 0}, {-22, 0, 10, 0}, {0, 0, 0, 1}, {10, 0, -22, 0}}] ;[o] 0 1 0 0 -22 0 10 0 0 0 0 1 10 0 -22 0 :[font = input; initialization; preserveAspect; startGroup] *) Clear[K] A=MatrixExp[M t]; u=Transpose[{Array[Sum[%[[#,j]]K[j],{j,4}]&,4]}]//Expand; b={10,0,12,0} (* :[font = output; output; inactive; preserveAspect; endGroup] {10, 0, 12, 0} ;[o] {10, 0, 12, 0} :[font = input; initialization; preserveAspect; startGroup] *) LinearSolve[A/.{t->0},b]; Do[K[i]=%[[i]],{i,4}] y={u[[1]],u[[3]]}//ComplexExpand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-Cos[4*2^(1/2)*t] + 11*Cos[2*3^(1/2)*t]}, {Cos[4*2^(1/2)*t] + 11*Cos[2*3^(1/2)*t]}}] ;[o] -Cos[4 Sqrt[2] t] + 11 Cos[2 Sqrt[3] t] Cos[4 Sqrt[2] t] + 11 Cos[2 Sqrt[3] t] :[font = input; initialization; preserveAspect] *) Problems on Linear Recurrence Systems (* :[font = input; initialization; preserveAspect] *) <0})-1000000.0==0,R[1][0]]//Expand; Solve[(p[[2]]/.{n->0}/.%)-1000000.0==0,R[2][0]]//Expand; p[[1]]/.{n->{1,2,3,4,5,6,7,8,9,10}}/.%%/.%//N//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{5000., 41.66666666666666667, 0.3194444444444444445, 0.002476851851851851852, 0.00001917438271604938272, 1.484696502057613169*10^-7, 1.149584190672153635*10^-9, 8.90114168952903521*10^-12, 6.892081285246151503*10^-14, 5.336482664291520603*10^-16}}}} ;[o] {{{{5000., 41.6667, 0.319444, 0.00247685, 0.0000191744, -7 -9 -12 1.4847 10 , 1.14958 10 , 8.90114 10 , -14 -16 6.89208 10 , 5.33648 10 }}}} :[font = input; initialization; preserveAspect; startGroup] *) p[[2]]/.{n->{1,2,3,4,5,6,7,8,9,10}}/.%%%/.%%//N//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] {{{{1666.666666666666667, 19.44444444444444444, 0.1435185185185185185, 0.001118827160493827161, 8.654835390946502059*10^-6, 6.702246227709190673*10^-8, 5.189400434385002287*10^-10, 4.018120808565767414*10^-12, 3.1111972419092618*10^-14, 2.408974895319988485*10^-16}}}} ;[o] -6 {{{{1666.67, 19.4444, 0.143519, 0.00111883, 8.65484 10 , -8 -10 -12 6.70225 10 , 5.1894 10 , 4.01812 10 , -14 -16 3.1112 10 , 2.40897 10 }}}} :[font = input; initialization; preserveAspect] *) b) (* :[font = input; initialization; preserveAspect] *) Looking at the expressions for p[[1]] and p[[2]] as functions of n above, we see that both are exponentials of basis < 1 in n and therefore the populations will go extinct quite rapidly, no matter the initial numbers. (* :[font = input; initialization; preserveAspect] *) Problem 2 (* :[font = input; initialization; preserveAspect; startGroup] *) M={{1,1,0}, \ {-1,2,1}, \ {-1,-1,4}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, 1, 0}, {-1, 2, 1}, {-1, -1, 4}}] ;[o] 1 1 0 -1 2 1 -1 -1 4 :[font = input; initialization; preserveAspect; startGroup] *) EV=Eigensystem[M][[2]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, 1, 1}, {0, 0, 0}, {1, 2, 3}}] ;[o] 1 1 1 0 0 0 1 2 3 :[font = input; initialization; preserveAspect; startGroup] *) NullSpace[EV] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, -2, 1}}] ;[o] 1 -2 1 :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Join[{EV[[1]]},{EV[[3]]},%]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, 1, 1}, {1, 2, -2}, {1, 3, 1}}] ;[o] 1 1 1 1 2 -2 1 3 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P//Together (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2, 0, -6}, {0, 3, 3}, {0, 0, 2}}] ;[o] 2 0 -6 0 3 3 0 0 2 :[font = input; initialization; preserveAspect] *) Having now upper triangularized our system of recurrence equations, we "RSolve" it in a do-loop in the order 3,2,1. (* :[font = input; initialization; preserveAspect; startGroup] *) r=Array[0&,3]; Do[r[[4-i]]=R[4-i][n]/.RSolve[R[4-i][n+1]==T[[4-i,4-i]]R[4-i][n] \ +Sum[T[[4-i,j]]r[[j,1]],{j,5-i,3}], \ R[4-i][n],n],{i,3}] r//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2^n*R[1][0] - 3*2^n*n*R[3][0]}, {3^n*R[2][0] - 3*2^n*R[3][0] + 3*3^n*R[3][0]}, {2^n*R[3][0]}}] ;[o] n n 2 R[1][0] - 3 2 n R[3][0] n n n 3 R[2][0] - 3 2 R[3][0] + 3 3 R[3][0] n 2 R[3][0] :[font = input; initialization; preserveAspect; startGroup] *) p=P.r//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{2^n*R[1][0] + 3^n*R[2][0] - 2*2^n*R[3][0] + 3*3^n*R[3][0] - 3*2^n*n*R[3][0]}, {2^n*R[1][0] + 2*3^n*R[2][0] - 8*2^n*R[3][0] + 6*3^n*R[3][0] - 3*2^n*n*R[3][0]}, {2^n*R[1][0] + 3*3^n*R[2][0] - 8*2^n*R[3][0] + 9*3^n*R[3][0] - 3*2^n*n*R[3][0]}}] ;[o] n n n n 2 R[1][0] + 3 R[2][0] - 2 2 R[3][0] + 3 3 R[3][0] - n 3 2 n R[3][0] n n n n 2 R[1][0] + 2 3 R[2][0] - 8 2 R[3][0] + 6 3 R[3][0] - n 3 2 n R[3][0] n n n n 2 R[1][0] + 3 3 R[2][0] - 8 2 R[3][0] + 9 3 R[3][0] - n 3 2 n R[3][0] :[font = input; initialization; preserveAspect; startGroup] *) Clear[R]; R[1][0]:=1; R[2][0]:=1; R[3][0]:=1; p/.{n->0} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{3}, {1}, {5}}] ;[o] 3 1 5 :[font = input; initialization; preserveAspect; startGroup] *) p/.{n->10} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{204452}, {434504}, {670700}}] ;[o] 204452 434504 670700 :[font = input; initialization; preserveAspect; startGroup] *) Clear[R]; R[1][0]:=1; R[2][0]:=1; R[3][0]:=-1; p/.{n->0} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1}, {5}, {3}}] ;[o] 1 5 3 :[font = input; initialization; preserveAspect; startGroup] *) p/.{n->10} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-84306}, {-196260}, {-314358}}] ;[o] -84306 -196260 -314358 :[font = input; initialization; preserveAspect] *) As one can guess from the above tests, the future is dependent on the initial populations. For instance, for p[0]={3,1,5}, the populations would subsequenly grow indefinitely, whereis for p[0]={1,5,3} they go extinct. (* :[font = input; initialization; preserveAspect] *) Exercises on Quadratics (* :[font = input; initialization; preserveAspect] *) Exercise 1 (* :[font = input; initialization; preserveAspect; startGroup] *) Clear[x]; X=Array[Subscripted[x[#]]&,2] (* :[font = output; output; inactive; preserveAspect; endGroup] {Subscripted[x[1]], Subscripted[x[2]]} ;[o] {x , x } 1 2 :[font = input; initialization; preserveAspect; startGroup] *) Clear[y]; Y=Array[Subscripted[y[#]]&,2] (* :[font = output; output; inactive; preserveAspect; endGroup] {Subscripted[y[1]], Subscripted[y[2]]} ;[o] {y , y } 1 2 :[font = input; initialization; preserveAspect] *) a) (* :[font = input; initialization; preserveAspect; startGroup] *) M={{3,-4},{-4,-3}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{3, -4}, {-4, -3}}] ;[o] 3 -4 -4 -3 :[font = input; initialization; preserveAspect; startGroup] *) X.M.X//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] 3*Subscripted[x[1]]^2 - 8*Subscripted[x[1]]* Subscripted[x[2]] - 3*Subscripted[x[2]]^2 ;[o] 2 2 3 x - 8 x x - 3 x 1 1 2 2 :[font = input; initialization; preserveAspect; startGroup] *) S=Solve[%-1==0,X[[2]]]//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{Subscripted[x[2]] -> (-8*Subscripted[x[1]] - (-12 + 100*Subscripted[x[1]]^2)^(1/2))/6}, {Subscripted[x[2]] -> (-8*Subscripted[x[1]] + (-12 + 100*Subscripted[x[1]]^2)^(1/2))/6}}] ;[o] 2 -8 x - Sqrt[-12 + 100 x ] 1 1 x -> --------------------------- 2 6 2 -8 x + Sqrt[-12 + 100 x ] 1 1 x -> --------------------------- 2 6 :[font = input; initialization; preserveAspect; startGroup] *) Clear[f] f[i_][x1_]:=(X[[2]]/.S[[i]])/.{X[[1]]->x1} P1=Plot[{f[1][x1],f[2][x1]},{x1,-2,-Sqrt[12.001]/10}] P2=Plot[{f[1][x1],f[2][x1]},{x1,Sqrt[12.001]/10,2}] Show[P1,P2] (* :[font = postscript; PostScript; formatAsPostScript; output; inactive; preserveAspect; pictureLeft = 34; pictureWidth = 282; pictureHeight = 174] %! 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.50688 L s P [(4)] .4875 .50688 1 0 Mshowa p .002 w .5 .60581 m .50625 .60581 L s P [(6)] .4875 .60581 1 0 Mshowa p .001 w .5 .03201 m .50375 .03201 L s P p .001 w .5 .0518 m .50375 .0518 L s P p .001 w .5 .07158 m .50375 .07158 L s P p .001 w .5 .09137 m .50375 .09137 L s P p .001 w .5 .13094 m .50375 .13094 L s P p .001 w .5 .15073 m .50375 .15073 L s P p .001 w .5 .17051 m .50375 .17051 L s P p .001 w .5 .1903 m .50375 .1903 L s P p .001 w .5 .22987 m .50375 .22987 L s P p .001 w .5 .24966 m .50375 .24966 L s P p .001 w .5 .26944 m .50375 .26944 L s P p .001 w .5 .28923 m .50375 .28923 L s P p .001 w .5 .3288 m .50375 .3288 L s P p .001 w .5 .34859 m .50375 .34859 L s P p .001 w .5 .36838 m .50375 .36838 L s P p .001 w .5 .38816 m .50375 .38816 L s P p .001 w .5 .42773 m .50375 .42773 L s P p .001 w .5 .44752 m .50375 .44752 L s P p .001 w .5 .46731 m .50375 .46731 L s P p .001 w .5 .48709 m .50375 .48709 L s P p .001 w .5 .52667 m .50375 .52667 L s P p .001 w .5 .54645 m .50375 .54645 L s P p .001 w .5 .56624 m .50375 .56624 L s P p .001 w .5 .58602 m .50375 .58602 L s P p .002 w .5 0 m .5 .61803 L s P P 0 0 m 1 0 L 1 .61803 L 0 .61803 L closepath clip newpath p p p p .004 w .02381 .27853 m .04021 .27976 L .05662 .28099 L .07302 .28223 L .08943 .28348 L .10583 .28474 L .12224 .28601 L .13864 .2873 L .15505 .28859 L .17145 .28991 L .18785 .29124 L .20426 .2926 L .22066 .29398 L .23707 .2954 L .25347 .29686 L .26988 .29837 L .28628 .29995 L .30269 .30161 L .31909 .30338 L .3355 .3053 L .3519 .30745 L .3683 .30995 L .37651 .3114 L .38471 .31306 L .39291 .31503 L .40111 .31752 L .40521 .3191 L .40932 .32108 L .41137 .32233 L .41342 .32388 L .41444 .32484 L .41547 .32602 L .41598 .32674 L .41649 .32762 L .41701 .32881 L .41752 .3316 L s P P p p .004 w .02381 .60332 m .04021 .593 L .05662 .58268 L .07302 .57235 L .08943 .56202 L .10583 .55167 L .12224 .54131 L .13864 .53094 L .15505 .52055 L .17145 .51015 L .18785 .49973 L .20426 .48928 L .22066 .47881 L .23707 .4683 L .25347 .45775 L .26988 .44715 L .28628 .43649 L .30269 .42574 L .31909 .41488 L .3355 .40387 L .3519 .39263 L .3683 .38105 L .38471 .36885 L .40111 .3553 L .40932 .34719 L .41342 .34212 L .41547 .33885 L .41649 .33667 L .41701 .33521 L .41752 .33213 L s P P P p p p .004 w .58248 .28591 m .58299 .28283 L .58351 .28136 L .58402 .2802 L .58453 .27919 L .58658 .27591 L .59068 .27084 L .59889 .26274 L .60709 .2557 L .61529 .24919 L .6317 .23699 L .6481 .2254 L .6645 .21416 L .68091 .20315 L .69731 .19229 L .71372 .18155 L .73012 .17088 L .74653 .16028 L .76293 .14974 L .77934 .13923 L .79574 .12875 L .81215 .11831 L .82855 .10789 L .84495 .09748 L .86136 .0871 L .87776 .07673 L .89417 .06637 L .91057 .05602 L .92698 .04568 L .94338 .03535 L .95979 .02503 L .97619 .01472 L s P P p p .004 w .58248 .28643 m .58299 .28923 L .58351 .29041 L .58402 .29129 L .58453 .29201 L .58658 .29415 L .58863 .2957 L .59068 .29695 L .59889 .30051 L .60299 .30184 L .60709 .303 L .61529 .30497 L .6317 .30809 L .6481 .31058 L .6645 .31273 L .68091 .31466 L .69731 .31643 L .71372 .31808 L .73012 .31966 L .74653 .32117 L .76293 .32263 L .77934 .32405 L .79574 .32543 L .81215 .32679 L .82855 .32813 L .84495 .32944 L .86136 .33074 L .87776 .33202 L .89417 .33329 L .91057 .33455 L .92698 .3358 L .94338 .33704 L .95979 .33828 L .97619 .3395 L s P P P P % End of Graphics MathPictureEnd :[font = output; output; inactive; preserveAspect; endGroup] Graphics["<<>>"] ;[o] -Graphics- :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, -2}, {2, 1}}] ;[o] 1 -2 2 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-5, 0}, {0, 5}}] ;[o] -5 0 0 5 :[font = input; initialization; preserveAspect; startGroup] *) Print[Y.T.Y,"=1"] (* :[font = print; inactive; preserveAspect; endGroup] 2 2 -5 y + 5 y =1 1 2 :[font = input; initialization; preserveAspect] *) b) (* :[font = input; initialization; preserveAspect; startGroup] *) M={{0,1/2},{1/2,0}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{0, 1/2}, {1/2, 0}}] ;[o] 1 - 0 2 1 - 2 0 :[font = input; initialization; preserveAspect; startGroup] *) X.M.X (* :[font = output; output; inactive; preserveAspect; endGroup] Subscripted[x[1]]*Subscripted[x[2]] ;[o] x x 1 2 :[font = input; initialization; preserveAspect; startGroup] *) S=Solve[%-1==0,X[[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{Subscripted[x[2]] -> Subscripted[x[1]]^(-1)}}] ;[o] 1 x -> -- 2 x 1 :[font = input; initialization; preserveAspect; startGroup] *) Plot[f[1][x1],{x1,-2,2}] (* :[font = postscript; PostScript; formatAsPostScript; output; inactive; preserveAspect; pictureLeft = 34; pictureWidth = 282; pictureHeight = 174] %! %%Creator: Mathematica %%AspectRatio: .61803 MathPictureStart %% Graphics /Courier findfont 10 scalefont setfont % Scaling calculations 0.5 0.238095 0.313345 0.00649195 [ [(-2)] .02381 .31334 0 2 Msboxa [(-1)] .2619 .31334 0 2 Msboxa [(1)] .7381 .31334 0 2 Msboxa [(2)] .97619 .31334 0 2 Msboxa [(-40)] .4875 .05367 1 0 Msboxa [(-20)] .4875 .18351 1 0 Msboxa [(20)] .4875 .44318 1 0 Msboxa [(40)] .4875 .57302 1 0 Msboxa [ -0.001 -0.001 0 0 ] [ 1.001 .61903 0 0 ] ] MathScale % Start of Graphics 1 setlinecap 1 setlinejoin newpath [ ] 0 setdash 0 g p p .002 w .02381 .31334 m .02381 .31959 L s P [(-2)] .02381 .31334 0 2 Mshowa p .002 w .2619 .31334 m .2619 .31959 L s P [(-1)] .2619 .31334 0 2 Mshowa p .002 w .7381 .31334 m .7381 .31959 L s P [(1)] .7381 .31334 0 2 Mshowa p .002 w .97619 .31334 m .97619 .31959 L s P [(2)] .97619 .31334 0 2 Mshowa p .001 w .07143 .31334 m .07143 .31709 L s P p .001 w .11905 .31334 m .11905 .31709 L s P p .001 w .16667 .31334 m .16667 .31709 L s P p .001 w .21429 .31334 m .21429 .31709 L s P p .001 w .30952 .31334 m .30952 .31709 L s P p .001 w .35714 .31334 m .35714 .31709 L s P p .001 w .40476 .31334 m .40476 .31709 L s P p .001 w .45238 .31334 m .45238 .31709 L s P p .001 w .54762 .31334 m .54762 .31709 L s P p .001 w .59524 .31334 m .59524 .31709 L s P p .001 w .64286 .31334 m .64286 .31709 L s P p .001 w .69048 .31334 m .69048 .31709 L s P p .001 w .78571 .31334 m .78571 .31709 L s P p .001 w .83333 .31334 m .83333 .31709 L s P p .001 w .88095 .31334 m .88095 .31709 L s P p .001 w .92857 .31334 m .92857 .31709 L s P p .002 w 0 .31334 m 1 .31334 L s P p .002 w .5 .05367 m .50625 .05367 L s P [(-40)] .4875 .05367 1 0 Mshowa p .002 w .5 .18351 m .50625 .18351 L s P [(-20)] .4875 .18351 1 0 Mshowa p .002 w .5 .44318 m .50625 .44318 L s P [(20)] .4875 .44318 1 0 Mshowa p .002 w .5 .57302 m .50625 .57302 L s P [(40)] .4875 .57302 1 0 Mshowa p .001 w .5 .07963 m .50375 .07963 L s P p .001 w .5 .1056 m .50375 .1056 L s P p .001 w .5 .13157 m .50375 .13157 L s P p .001 w .5 .15754 m .50375 .15754 L s P p .001 w .5 .20947 m .50375 .20947 L s P p .001 w .5 .23544 m .50375 .23544 L s P p .001 w .5 .26141 m .50375 .26141 L s P p .001 w .5 .28738 m .50375 .28738 L s P p .001 w .5 .33931 m .50375 .33931 L s P p .001 w .5 .36528 m .50375 .36528 L s P p .001 w .5 .39125 m .50375 .39125 L s P p .001 w .5 .41722 m .50375 .41722 L s P p .001 w .5 .46915 m .50375 .46915 L s P p .001 w .5 .49512 m .50375 .49512 L s P p .001 w .5 .52109 m .50375 .52109 L s P p .001 w .5 .54706 m .50375 .54706 L s P p .001 w .5 .0277 m .50375 .0277 L s P p .001 w .5 .00173 m .50375 .00173 L s P p .001 w .5 .59899 m .50375 .59899 L s P p .002 w .5 0 m .5 .61803 L s P P 0 0 m 1 0 L 1 .61803 L 0 .61803 L closepath clip newpath p p .004 w .02381 .3101 m .06349 .3098 L .10317 .30945 L .14286 .30902 L .18254 .30848 L .22222 .30778 L .2619 .30685 L .28175 .30626 L .30159 .30555 L .32143 .30469 L .34127 .30361 L .36111 .30222 L .38095 .30036 L .39087 .29918 L .40079 .29776 L .41071 .29603 L .42063 .29387 L .43056 .29109 L .44048 .28738 L .4504 .28218 L .45536 .27872 L .46032 .27439 L .46528 .26883 L .47024 .26141 L .4752 .25102 L .47768 .2441 L .48016 .23544 L .48264 .22431 L .48512 .20947 L .4876 .1887 L .48884 .17485 L .49008 .15754 L .49132 .13528 L .49256 .1056 L .4938 .06405 L .49504 .00173 L s .49506 0 m .49504 .00173 L s s s s .50124 0 m .50124 .61803 L s s .50124 .61803 m .50124 0 L s s s s .5051 .61803 m .5062 .56264 L s .5062 .56264 m .50744 .52109 L .50868 .49141 L .50992 .46915 L .51116 .45184 L .5124 .43799 L .51488 .41722 L .51736 .40238 L .51984 .39125 L .52232 .38259 L .5248 .37567 L .52976 .36528 L .53472 .35786 L .53968 .3523 L .54464 .34797 L .5496 .34451 L .55952 .33931 L .56944 .3356 L .57937 .33282 L .58929 .33066 L .59921 .32893 L .61905 .32633 L .63889 .32447 L .65873 .32308 L .67857 .322 L .69841 .32114 L .7381 .31984 L .77778 .31891 L .81746 .31821 L .85714 .31767 L .89683 .31724 L .93651 .31689 L .97619 .31659 L s P P % End of Graphics MathPictureEnd :[font = output; output; inactive; preserveAspect; endGroup] Graphics["<<>>"] ;[o] -Graphics- :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-1, 1}, {1, 1}}] ;[o] -1 1 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-1/2, 0}, {0, 1/2}}] ;[o] 1 -(-) 2 0 1 - 0 2 :[font = input; initialization; preserveAspect; startGroup] *) Print[Y.T.Y,"=1"] (* :[font = print; inactive; preserveAspect; endGroup] 2 2 -y y 1 2 ---- + ---=1 2 2 :[font = input; initialization; preserveAspect] *) c) (* :[font = input; initialization; preserveAspect; startGroup] *) M={{5,3},{3,3}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{5, 3}, {3, 3}}] ;[o] 5 3 3 3 :[font = input; initialization; preserveAspect; startGroup] *) X.M.X//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] 5*Subscripted[x[1]]^2 + 6*Subscripted[x[1]]* Subscripted[x[2]] + 3*Subscripted[x[2]]^2 ;[o] 2 2 5 x + 6 x x + 3 x 1 1 2 2 :[font = input; initialization; preserveAspect; startGroup] *) S=Solve[%-8==0,X[[2]]]//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{Subscripted[x[2]] -> -Subscripted[x[1]] - (2/3)^(1/2)*(4 - Subscripted[x[1]]^2)^(1/2)}, {Subscripted[x[2]] -> -Subscripted[x[1]] + (2/3)^(1/2)*(4 - Subscripted[x[1]]^2)^(1/2)}}] ;[o] 2 2 x -> -x - Sqrt[-] Sqrt[4 - x ] 2 1 3 1 2 2 x -> -x + Sqrt[-] Sqrt[4 - x ] 2 1 3 1 :[font = input; initialization; preserveAspect; startGroup] *) Plot[{f[1][x1],f[2][x1]},{x1,-2,2}] (* :[font = postscript; PostScript; formatAsPostScript; output; inactive; preserveAspect; pictureLeft = 34; pictureWidth = 282; pictureHeight = 174] %! %%Creator: Mathematica %%AspectRatio: .61803 MathPictureStart %% Graphics /Courier findfont 10 scalefont setfont % Scaling calculations 0.5 0.238095 0.309017 0.113983 [ [(-2)] .02381 .30902 0 2 Msboxa [(-1)] .2619 .30902 0 2 Msboxa [(1)] .7381 .30902 0 2 Msboxa [(2)] .97619 .30902 0 2 Msboxa [(-2)] .4875 .08105 1 0 Msboxa [(-1)] .4875 .19503 1 0 Msboxa [(1)] .4875 .423 1 0 Msboxa [(2)] .4875 .53698 1 0 Msboxa [ -0.001 -0.001 0 0 ] [ 1.001 .61903 0 0 ] ] MathScale % Start of Graphics 1 setlinecap 1 setlinejoin newpath [ ] 0 setdash 0 g p p .002 w .02381 .30902 m .02381 .31527 L s P [(-2)] .02381 .30902 0 2 Mshowa p .002 w .2619 .30902 m .2619 .31527 L s P [(-1)] .2619 .30902 0 2 Mshowa p .002 w .7381 .30902 m .7381 .31527 L s P [(1)] .7381 .30902 0 2 Mshowa p .002 w .97619 .30902 m .97619 .31527 L s P [(2)] .97619 .30902 0 2 Mshowa p .001 w .07143 .30902 m .07143 .31277 L s P p .001 w .11905 .30902 m .11905 .31277 L s P p .001 w .16667 .30902 m .16667 .31277 L s P p .001 w .21429 .30902 m .21429 .31277 L s P p .001 w .30952 .30902 m .30952 .31277 L s P p .001 w .35714 .30902 m .35714 .31277 L s P p .001 w .40476 .30902 m .40476 .31277 L s P p .001 w .45238 .30902 m .45238 .31277 L s P p .001 w .54762 .30902 m .54762 .31277 L s P p .001 w .59524 .30902 m .59524 .31277 L s P p .001 w .64286 .30902 m .64286 .31277 L s P p .001 w .69048 .30902 m .69048 .31277 L s P p .001 w .78571 .30902 m .78571 .31277 L s P p .001 w .83333 .30902 m .83333 .31277 L s P p .001 w .88095 .30902 m .88095 .31277 L s P p .001 w .92857 .30902 m .92857 .31277 L s P p .002 w 0 .30902 m 1 .30902 L s P p .002 w .5 .08105 m .50625 .08105 L s P [(-2)] .4875 .08105 1 0 Mshowa p .002 w .5 .19503 m .50625 .19503 L s P [(-1)] .4875 .19503 1 0 Mshowa p .002 w .5 .423 m .50625 .423 L s P [(1)] .4875 .423 1 0 Mshowa p .002 w .5 .53698 m .50625 .53698 L s P [(2)] .4875 .53698 1 0 Mshowa p .001 w .5 .10385 m .50375 .10385 L s P p .001 w .5 .12664 m .50375 .12664 L s P p .001 w .5 .14944 m .50375 .14944 L s P p .001 w .5 .17224 m .50375 .17224 L s P p .001 w .5 .21783 m .50375 .21783 L s P p .001 w .5 .24063 m .50375 .24063 L s P p .001 w .5 .26342 m .50375 .26342 L s P p .001 w .5 .28622 m .50375 .28622 L s P p .001 w .5 .33181 m .50375 .33181 L s P p .001 w .5 .35461 m .50375 .35461 L s P p .001 w .5 .37741 m .50375 .37741 L s P p .001 w .5 .4002 m .50375 .4002 L s P p .001 w .5 .4458 m .50375 .4458 L s P p .001 w .5 .46859 m .50375 .46859 L s P p .001 w .5 .49139 m .50375 .49139 L s P p .001 w .5 .51419 m .50375 .51419 L s P p .001 w .5 .05825 m .50375 .05825 L s P p .001 w .5 .03546 m .50375 .03546 L s P p .001 w .5 .01266 m .50375 .01266 L s P p .001 w .5 .55978 m .50375 .55978 L s P p .001 w .5 .58258 m .50375 .58258 L s P p .001 w .5 .60537 m .50375 .60537 L s P p .002 w .5 0 m .5 .61803 L s P P 0 0 m 1 0 L 1 .61803 L 0 .61803 L closepath clip newpath p p p .004 w .02381 .53698 m .02505 .52296 L .02629 .51682 L .02877 .50781 L .03125 .50065 L .03373 .49444 L .04365 .47431 L .05357 .45796 L .06349 .4436 L .10317 .3961 L .14286 .35688 L .18254 .32226 L .22222 .29081 L .2619 .2618 L .30159 .2348 L .34127 .20952 L .38095 .18579 L .42063 .16348 L .46032 .14253 L .5 .12288 L .53968 .10453 L .57937 .08749 L .61905 .0718 L .65873 .05754 L .69841 .04483 L .7381 .03384 L .77778 .02485 L .79762 .02124 L .81746 .0183 L .82738 .01712 L .8373 .01615 L .84226 .01575 L .84722 .01541 L .85218 .01514 L .85466 .01502 L .85714 .01493 L .85962 .01485 L .86086 .01482 L .8621 .01479 L .86334 .01476 L .86458 .01474 L .86582 .01473 L .86706 .01472 L .8683 .01472 L .86954 .01472 L .87078 .01472 L .87202 .01473 L .87326 .01475 L .8745 .01477 L .87574 .01479 L Mistroke .87698 .01483 L .88194 .01501 L .88442 .01514 L .8869 .01529 L .89187 .01567 L .89683 .01616 L .90179 .01677 L .90675 .01751 L .91667 .01944 L .92659 .02208 L .93651 .02566 L .94643 .03053 L .95139 .03364 L .95635 .03738 L .96131 .04201 L .96379 .04479 L .96627 .048 L .96875 .05184 L .97123 .05663 L .97247 .05961 L .97371 .06327 L .97495 .06822 L .97619 .08105 L Mfstroke P P p p .004 w .02381 .53698 m .02505 .54981 L .02629 .55477 L .02877 .5614 L .03125 .5662 L .03373 .57003 L .03869 .57603 L .04365 .58065 L .05357 .58751 L .06349 .59237 L .07341 .59595 L .08333 .5986 L .08829 .59964 L .09325 .60053 L .09821 .60127 L .10317 .60188 L .10813 .60237 L .1131 .60275 L .11558 .6029 L .11806 .60303 L .12054 .60313 L .12302 .60321 L .12426 .60324 L .1255 .60327 L .12674 .60329 L .12798 .6033 L .12922 .60331 L .13046 .60332 L .1317 .60332 L .13294 .60331 L .13418 .6033 L .13542 .60329 L .1379 .60325 L .13914 .60322 L .14038 .60319 L .14286 .60311 L .14782 .6029 L .15278 .60262 L .1627 .60188 L .17262 .60091 L .18254 .59973 L .22222 .59318 L .2619 .5842 L .30159 .57321 L .34127 .56049 L .38095 .54623 L .42063 .53054 L .46032 .5135 L .5 .49515 L .53968 .47551 L Mistroke .57937 .45455 L .61905 .43225 L .65873 .40852 L .69841 .38324 L .7381 .35623 L .77778 .32722 L .81746 .29578 L .85714 .26116 L .89683 .22193 L .93651 .17444 L .95635 .14372 L .96131 .13434 L .96627 .1236 L .96875 .11739 L .97123 .11022 L .97371 .10121 L .97495 .09507 L .97619 .08105 L Mfstroke P P P % End of Graphics MathPictureEnd :[font = output; output; inactive; preserveAspect; endGroup] Graphics["<<>>"] ;[o] -Graphics- :[font = input; initialization; preserveAspect; startGroup] *) P=Transpose[Eigensystem[M][[2]]] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{(1 - 10^(1/2))/3, (1 + 10^(1/2))/3}, {1, 1}}] ;[o] 1 - Sqrt[10] 1 + Sqrt[10] ------------ ------------ 3 3 1 1 :[font = input; initialization; preserveAspect; startGroup] *) T=Inverse[P].M.P//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{4 - 10^(1/2), 0}, {0, 4 + 10^(1/2)}}] ;[o] 4 - Sqrt[10] 0 0 4 + Sqrt[10] :[font = input; initialization; preserveAspect; startGroup] *) Print[Y.T.Y,"=8"] (* :[font = print; inactive; preserveAspect; endGroup] 2 2 (4 - Sqrt[10]) y + (4 + Sqrt[10]) y =8 1 2 :[font = input; initialization; preserveAspect] *) d) (* :[font = input; initialization; preserveAspect; startGroup] *) M={{-1,0}, \ {0,1}} (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{-1, 0}, {0, 1}}] ;[o] -1 0 0 1 :[font = input; initialization; preserveAspect; startGroup] *) k={-2,0}; X.M.X+X.k (* :[font = output; output; inactive; preserveAspect; endGroup] -2*Subscripted[x[1]] - Subscripted[x[1]]^2 + Subscripted[x[2]]^2 ;[o] 2 2 -2 x - x + x 1 1 2 :[font = input; initialization; preserveAspect; startGroup] *) Solve[%-1==0,X[[2]]]//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{Subscripted[x[2]] -> -1 - Subscripted[x[1]]}, {Subscripted[x[2]] -> 1 + Subscripted[x[1]]}}] ;[o] x -> -1 - x 2 1 x -> 1 + x 2 1 :[font = input; initialization; preserveAspect; startGroup] *) Plot[{1+x1,-1-x1},{x1,-3,1}] (* :[font = postscript; PostScript; formatAsPostScript; output; inactive; preserveAspect; pictureLeft = 34; pictureWidth = 282; pictureHeight = 174] %! %%Creator: Mathematica %%AspectRatio: .61803 MathPictureStart %% Graphics /Courier findfont 10 scalefont setfont % Scaling calculations 0.738095 0.238095 0.309017 0.147151 [ [(-3)] .02381 .30902 0 2 Msboxa [(-2)] .2619 .30902 0 2 Msboxa [(-1)] .5 .30902 0 2 Msboxa [(1)] .97619 .30902 0 2 Msboxa [(-2)] .7256 .01472 1 0 Msboxa [(-1)] .7256 .16187 1 0 Msboxa [(1)] .7256 .45617 1 0 Msboxa [(2)] .7256 .60332 1 0 Msboxa [ -0.001 -0.001 0 0 ] [ 1.001 .61903 0 0 ] ] MathScale % Start of Graphics 1 setlinecap 1 setlinejoin newpath [ ] 0 setdash 0 g p p .002 w .02381 .30902 m .02381 .31527 L s P [(-3)] .02381 .30902 0 2 Mshowa p .002 w .2619 .30902 m .2619 .31527 L s P [(-2)] .2619 .30902 0 2 Mshowa p .002 w .5 .30902 m .5 .31527 L s P [(-1)] .5 .30902 0 2 Mshowa p .002 w .97619 .30902 m .97619 .31527 L s P [(1)] .97619 .30902 0 2 Mshowa p .001 w .07143 .30902 m .07143 .31277 L s P p .001 w .11905 .30902 m .11905 .31277 L s P p .001 w .16667 .30902 m .16667 .31277 L s P p .001 w .21429 .30902 m .21429 .31277 L s P p .001 w .30952 .30902 m .30952 .31277 L s P p .001 w .35714 .30902 m .35714 .31277 L s P p .001 w .40476 .30902 m .40476 .31277 L s P p .001 w .45238 .30902 m .45238 .31277 L s P p .001 w .54762 .30902 m .54762 .31277 L s P p .001 w .59524 .30902 m .59524 .31277 L s P p .001 w .64286 .30902 m .64286 .31277 L s P p .001 w .69048 .30902 m .69048 .31277 L s P p .001 w .78571 .30902 m .78571 .31277 L s P p .001 w .83333 .30902 m .83333 .31277 L s P p .001 w .88095 .30902 m .88095 .31277 L s P p .001 w .92857 .30902 m .92857 .31277 L s P p .002 w 0 .30902 m 1 .30902 L s P p .002 w .7381 .01472 m .74435 .01472 L s P [(-2)] .7256 .01472 1 0 Mshowa p .002 w .7381 .16187 m .74435 .16187 L s P [(-1)] .7256 .16187 1 0 Mshowa p .002 w .7381 .45617 m .74435 .45617 L s P [(1)] .7256 .45617 1 0 Mshowa p .002 w .7381 .60332 m .74435 .60332 L s P [(2)] .7256 .60332 1 0 Mshowa p .001 w .7381 .04415 m .74185 .04415 L s P p .001 w .7381 .07358 m .74185 .07358 L s P p .001 w .7381 .10301 m .74185 .10301 L s P p .001 w .7381 .13244 m .74185 .13244 L s P p .001 w .7381 .1913 m .74185 .1913 L s P p .001 w .7381 .22073 m .74185 .22073 L s P p .001 w .7381 .25016 m .74185 .25016 L s P p .001 w .7381 .27959 m .74185 .27959 L s P p .001 w .7381 .33845 m .74185 .33845 L s P p .001 w .7381 .36788 m .74185 .36788 L s P p .001 w .7381 .39731 m .74185 .39731 L s P p .001 w .7381 .42674 m .74185 .42674 L s P p .001 w .7381 .4856 m .74185 .4856 L s P p .001 w .7381 .51503 m .74185 .51503 L s P p .001 w .7381 .54446 m .74185 .54446 L s P p .001 w .7381 .57389 m .74185 .57389 L s P p .002 w .7381 0 m .7381 .61803 L s P P 0 0 m 1 0 L 1 .61803 L 0 .61803 L closepath clip newpath p p p .004 w .02381 .01472 m .06349 .03924 L .10317 .06377 L .14286 .08829 L .18254 .11282 L .22222 .13734 L .2619 .16187 L .30159 .18639 L .34127 .21092 L .38095 .23544 L .42063 .25997 L .46032 .28449 L .5 .30902 L .53968 .33354 L .57937 .35807 L .61905 .38259 L .65873 .40712 L .69841 .43164 L .7381 .45617 L .77778 .48069 L .81746 .50522 L .85714 .52974 L .89683 .55427 L .93651 .57879 L .97619 .60332 L s P P p p .004 w .02381 .60332 m .06349 .57879 L .10317 .55427 L .14286 .52974 L .18254 .50522 L .22222 .48069 L .2619 .45617 L .30159 .43164 L .34127 .40712 L .38095 .38259 L .42063 .35807 L .46032 .33354 L .5 .30902 L .53968 .28449 L .57937 .25997 L .61905 .23544 L .65873 .21092 L .69841 .18639 L .7381 .16187 L .77778 .13734 L .81746 .11282 L .85714 .08829 L .89683 .06377 L .93651 .03924 L .97619 .01472 L s P P P % End of Graphics MathPictureEnd :[font = output; output; inactive; preserveAspect; endGroup] Graphics["<<>>"] ;[o] -Graphics- :[font = input; initialization; preserveAspect] *) In order to write this one in the standard form, we need the translation Y=X+{1,0}: (* :[font = input; initialization; preserveAspect; startGroup] *) X=Y-{1,0} (* :[font = output; output; inactive; preserveAspect; endGroup] {-1 + Subscripted[y[1]], Subscripted[y[2]]} ;[o] {-1 + y , y } 1 2 :[font = input; initialization; preserveAspect; startGroup] *) Print[(X.M.X+X.k-1)//Simplify,"=",1-1] (* :[font = print; inactive; preserveAspect; endGroup] 2 2 -y + y =0 1 2 :[font = input; initialization; preserveAspect] *) Exercise 2 (* :[font = input; initialization; preserveAspect; startGroup] *) X=Array[Subscripted[x[#]]&,3] Y=Array[Subscripted[y[#]]&,3] (* :[font = output; output; inactive; preserveAspect] {Subscripted[x[1]], Subscripted[x[2]], Subscripted[x[3]]} ;[o] {x , x , x } 1 2 3 :[font = output; output; inactive; preserveAspect; endGroup] {Subscripted[y[1]], Subscripted[y[2]], Subscripted[y[3]]} ;[o] {y , y , y } 1 2 3 :[font = input; initialization; preserveAspect] *) a) (* :[font = input; initialization; preserveAspect; startGroup] *) M=Table[If[i==j,1,-1],{i,3},{j,3}] (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{1, -1, -1}, {-1, 1, -1}, {-1, -1, 1}}] ;[o] 1 -1 -1 -1 1 -1 -1 -1 1 :[font = input; initialization; preserveAspect; startGroup] *) X.M.X//Expand (* :[font = output; output; inactive; preserveAspect; endGroup] Subscripted[x[1]]^2 - 2*Subscripted[x[1]]* Subscripted[x[2]] + Subscripted[x[2]]^2 - 2*Subscripted[x[1]]*Subscripted[x[3]] - 2*Subscripted[x[2]]*Subscripted[x[3]] + Subscripted[x[3]]^2 ;[o] 2 2 2 x - 2 x x + x - 2 x x - 2 x x + x 1 1 2 2 1 3 2 3 3 :[font = input; initialization; preserveAspect; startGroup] *) S=Solve[%-3==0,X[[3]]]//Simplify (* :[font = output; output; inactive; preserveAspect; endGroup] MatrixForm[{{Subscripted[x[3]] -> Subscripted[x[1]] + Subscripted[x[2]] - (3 + 4*Subscripted[x[1]]*Subscripted[x[2]])^(1/2)}, {Subscripted[x[3]] -> Subscripted[x[1]] + Subscripted[x[2]] + (3 + 4*Subscripted[x[1]]*Subscripted[x[2]])^(1/2)}}] ;[o] x -> x + x - Sqrt[3 + 4 x x ] 3 1 2 1 2 x -> x + x + Sqrt[3 + 4 x x ] 3 1 2 1 2 :[font = input; initialization; preserveAspect; startGroup] *) f[i_][x1_,x2_]:=(X[[3]]/.S[[i]])/.{X[[1]]->x1}/.{X[[2]]->x2} P1=Plot3D[f[1][x1,x2],{x1,-1/2,1/2},{x2,-3/2,3/2}] P2=Plot3D[f[2][x1,x2],{x1,-1/2,1/2},{x2,-3/2,3/2}] Show[P1,P2] (* :[font = postscript; PostScript; formatAsPostScript; output; inactive; preserveAspect; pictureLeft = 34; pictureWidth = 282; pictureHeight = 231] %! %%Creator: Mathematica %%AspectRatio: .82055 MathPictureStart %% SurfaceGraphics /Courier findfont 10 scalefont setfont % Scaling calculations 0.0249355 0.99742 -0.0396341 0.99742 [ [(-0.4)] .10672 .23696 1 .97179 Msboxa [(-0.2)] .22191 .19163 .94563 1 Msboxa [(0)] .34275 .1441 .86223 1 Msboxa [(0.2)] .46967 .09419 .77884 1 Msboxa [(0.4)] .60315 .04174 .69544 1 Msboxa [(-1)] .74399 .10162 -1 .37284 Msboxa [(0)] .83872 .24668 -1 .34028 Msboxa [(1)] .92081 .3724 -1 .31296 Msboxa [(-4)] .04523 .2932 1 -0.38736 Msboxa [(-2)] .03324 .36835 1 -0.37247 Msboxa [(0)] .02063 .44743 1 -0.35672 Msboxa [ 0 0 0 0 ] [ 1 .82055 0 0 ] ] MathScale % Start of Graphics 1 setlinecap 1 setlinejoin newpath [ ] 0 setdash 0 g p p .002 w .06024 .26735 m .67932 .02494 L s P p .002 w .11567 .24565 m .12014 .24999 L s P [(-0.4)] .10672 .23696 1 .97179 Mshowa p .002 w .23048 .20069 m .23476 .20522 L s P [(-0.2)] .22191 .19163 .94563 1 Mshowa p .002 w .35089 .15354 m .35496 .15826 L s P [(0)] .34275 .1441 .86223 1 Mshowa p .002 w .47733 .10403 m .48116 .10895 L s P [(0.2)] .46967 .09419 .77884 1 Mshowa p .002 w .61027 .05198 m .61382 .05709 L s P [(0.4)] .60315 .04174 .69544 1 Mshowa p .001 w .1382 .23682 m .14086 .23945 L s P p .001 w .16094 .22792 m .16358 .23057 L s P p .001 w .1839 .21893 m .18652 .2216 L s P p .001 w .20708 .20985 m .20967 .21255 L s P p .001 w .2541 .19144 m .25664 .19418 L s P p .001 w .27795 .1821 m .28047 .18487 L s P p .001 w .30203 .17267 m .30452 .17546 L s P p .001 w .32634 .16315 m .32881 .16596 L s P p .001 w .37568 .14383 m .3781 .14669 L s P p .001 w .40072 .13403 m .40311 .13691 L s P p .001 w .426 .12413 m .42836 .12703 L s P p .001 w .45154 .11413 m .45387 .11706 L s P p .001 w .50338 .09383 m .50565 .0968 L s P p .001 w .5297 .08352 m .53194 .08652 L s P p .001 w .55628 .07311 m .55849 .07614 L s P p .001 w .58314 .0626 m .58531 .06565 L s P p .001 w .09334 .25439 m .09605 .25697 L s P p .001 w .07122 .26305 m .07395 .26561 L s P p .001 w .63768 .04124 m .63978 .04434 L s P p .001 w .66537 .0304 m .66743 .03352 L s P P p p .002 w .67932 .02494 m .94594 .43277 L s P p .002 w .73231 .10598 m .72646 .10816 L s P [(-1)] .74399 .10162 -1 .37284 Mshowa p .002 w .82692 .2507 m .82101 .25271 L s P [(0)] .83872 .24668 -1 .34028 Mshowa p .002 w .90891 .37612 m .90296 .37799 L s P [(1)] .92081 .3724 -1 .31296 Mshowa p .001 w .75237 .13668 m .74886 .13796 L s P p .001 w .77184 .16646 m .76832 .16772 L s P p .001 w .79074 .19537 m .78721 .19661 L s P p .001 w .80909 .22343 m .80556 .22466 L s P p .001 w .84424 .2772 m .84069 .27838 L s P p .001 w .86108 .30296 m .85753 .30413 L s P p .001 w .87746 .32802 m .8739 .32917 L s P p .001 w .8934 .35239 m .88983 .35353 L s P p .001 w .71161 .07432 m .70811 .07565 L s P p .001 w .69026 .04166 m .68677 .04301 L s P p .001 w .92402 .39923 m .92044 .40033 L s P p .001 w .93873 .42173 m .93515 .42282 L s P P p p .002 w .06024 .26735 m .02494 .49015 L s P p .002 w .05686 .2887 m .06267 .28644 L s P [(-4)] .04523 .2932 1 -0.38736 Mshowa p .002 w .04493 .36399 m .05077 .36182 L s P [(-2)] .03324 .36835 1 -0.37247 Mshowa p .002 w .03237 .44324 m .03824 .44115 L s P [(0)] .02063 .44743 1 -0.35672 Mshowa p .001 w .05452 .30345 m .05801 .30211 L s P p .001 w .05216 .31836 m .05565 .31703 L s P p .001 w .04977 .33342 m .05327 .33209 L s P p .001 w .04736 .34863 m .05086 .34731 L s P p .001 w .04247 .37952 m .04598 .37822 L s P p .001 w .03998 .3952 m .04349 .39392 L s P p .001 w .03747 .41105 m .04099 .40977 L s P p .001 w .03493 .42706 m .03845 .4258 L s P p .001 w .05918 .27408 m .06266 .27272 L s P p .001 w .02978 .45959 m .0333 .45835 L s P p .001 w .02716 .47612 m .03069 .47488 L s P P 0 0 m 1 0 L 1 .82055 L 0 .82055 L closepath clip newpath p .002 w .06024 .26735 m .02494 .49015 L s .02494 .49015 m .40296 .79562 L s .40296 .79562 m .41001 .59401 L s .41001 .59401 m .06024 .26735 L s .67932 .02494 m .94594 .43277 L s .94594 .43277 m .97506 .64585 L s .97506 .64585 m .69286 .25814 L s .69286 .25814 m .67932 .02494 L s .06024 .26735 m .02494 .49015 L s .02494 .49015 m .69286 .25814 L s .69286 .25814 m .67932 .02494 L s .67932 .02494 m .06024 .26735 L s .41001 .59401 m .94594 .43277 L s .94594 .43277 m .97506 .64585 L s .97506 .64585 m .40296 .79562 L s .40296 .79562 m .41001 .59401 L s P p .664 .582 .753 r .0015 w .38225 .74011 .40314 .79053 .44063 .7591 .41939 .72385 Metetra .674 .644 .812 r .41939 .72385 .44063 .7591 .47799 .74175 .4569 .7093 Metetra .672 .659 .829 r .4569 .7093 .47799 .74175 .51573 .72655 .49486 .69561 Metetra .669 .669 .841 r .49486 .69561 .51573 .72655 .55392 .71239 .5333 .68241 Metetra .667 .676 .849 r .5333 .68241 .55392 .71239 .59259 .69883 .57227 .66952 Metetra .666 .682 .856 r .57227 .66952 .59259 .69883 .63179 .68565 .61178 .65683 Metetra .664 .688 .862 r .61178 .65683 .63179 .68565 .67153 .67271 .65186 .64426 Metetra .663 .692 .867 r .65186 .64426 .67153 .67271 .71183 .65993 .69252 .63175 Metetra .662 .696 .871 r .69252 .63175 .71183 .65993 .75272 .64724 .73379 .61927 Metetra .66 .7 .876 r .73379 .61927 .75272 .64724 .79421 .6346 .77569 .60678 Metetra .659 .703 .879 r .77569 .60678 .79421 .6346 .83633 .62197 .81823 .59426 Metetra .658 .706 .883 r .81823 .59426 .83633 .62197 .87909 .60933 .86144 .58168 Metetra .658 .709 .886 r .86144 .58168 .87909 .60933 .9225 .59665 .90533 .56904 Metetra .657 .712 .889 r .90533 .56904 .9225 .59665 .9666 .58391 .94992 .5563 Metetra .665 .634 .809 r .36052 .70336 .38225 .74011 .41939 .72385 .39772 .68989 Metetra .664 .65 .825 r .39772 .68989 .41939 .72385 .4569 .7093 .43539 .67695 Metetra .663 .66 .837 r .43539 .67695 .4569 .7093 .49486 .69561 .47356 .66433 Metetra .662 .668 .845 r .47356 .66433 .49486 .69561 .5333 .68241 .51226 .65191 Metetra .661 .675 .853 r .51226 .65191 .5333 .68241 .57227 .66952 .5515 .63961 Metetra .66 .681 .859 r .5515 .63961 .57227 .66952 .61178 .65683 .59132 .62737 Metetra .659 .686 .864 r .59132 .62737 .61178 .65683 .65186 .64426 .63173 .61515 Metetra .658 .69 .869 r .63173 .61515 .65186 .64426 .69252 .63175 .67276 .60291 Metetra .657 .694 .873 r .67276 .60291 .69252 .63175 .73379 .61927 .71441 .59064 Metetra .656 .698 .877 r .71441 .59064 .73379 .61927 .77569 .60678 .75671 .57831 Metetra .656 .702 .881 r .75671 .57831 .77569 .60678 .81823 .59426 .79968 .56591 Metetra .655 .705 .884 r .79968 .56591 .81823 .59426 .86144 .58168 .84334 .55341 Metetra .654 .708 .887 r .84334 .55341 .86144 .58168 .90533 .56904 .88771 .54081 Metetra .653 .712 .89 r .88771 .54081 .90533 .56904 .94992 .5563 .9328 .52809 Metetra .656 .642 .824 r .33829 .66832 .36052 .70336 .39772 .68989 .37561 .65633 Metetra .656 .652 .834 r .37561 .65633 .39772 .68989 .43539 .67695 .41344 .64446 Metetra .655 .66 .843 r .41344 .64446 .43539 .67695 .47356 .66433 .45182 .63265 Metetra .655 .667 .85 r .45182 .63265 .47356 .66433 .51226 .65191 .49075 .62087 Metetra .654 .673 .856 r .49075 .62087 .51226 .65191 .5515 .63961 .53027 .60907 Metetra .654 .679 .861 r .53027 .60907 .5515 .63961 .59132 .62737 .57039 .59724 Metetra .653 .684 .866 r .57039 .59724 .59132 .62737 .63173 .61515 .61113 .58535 Metetra .653 .688 .871 r .61113 .58535 .63173 .61515 .67276 .60291 .65251 .57339 Metetra .652 .693 .875 r .65251 .57339 .67276 .60291 .71441 .59064 .69455 .56133 Metetra .652 .697 .879 r .69455 .56133 .71441 .59064 .75671 .57831 .73726 .54917 Metetra .651 .7 .882 r .73726 .54917 .75671 .5783