What is multivariable calculus? 
(follow the instructions above to open this closed cell for a brief answer)

Many quantities in science depend on more than one variable.  For example, the Ideal Gas Law in chemistry and physics relates the pressure (P), volume (V), temperature (T), and amount (n - number of moles) of an "ideal" gas by the simple formula [Graphics:../Images/index_gr_1.gif], where [Graphics:../Images/index_gr_2.gif]  is a constant (depending on the units).  When some of these variables change, the others change in a way prescribed by this formula according to the rules that you learned in beginning calculus.

There are lots of examples of multivariate quantities in other subjects like statistics, economics, and of course, pure mathematics.  The formula [Graphics:../Images/index_gr_3.gif]  is just a simple example that we will use in the next section to help illustrate how Mathematica does calculus for you.

Converted by Mathematica      May 7, 2001