Implicit Differentiation 89 v1.0     By Jake Griffin (Jrock7286@aol.com)

impdiff is a function that returns the implicit derivative of a function of any number
of variables.  This makes multi variable calculus MUCH easier!

Syntax:
impdiff(equation, independant variable, dependant variable)

Examples:

Implicit derivative of x^2+y^2=36 with respect to x:
impdiff(x^2+y^2=36,x,y) -> -x/y

Implicit derivative of z^3+xyz=0 with respect to y:
impdiff(z^3+x*y*z=0,y,z) -> (-xz)/(xy+3z^2)