BC Calc Inverse Functions and derivatives

diamondbacker
Tue, 06 May 2008 20:22:01 +0000

If you don’t want to memorize, it is easy to derive:

If you use that if g(x) is the inverse of f(x), then:

g( f(x) ) = x

Using the chain rule:

g’( f(x) ) * f’(x) = 1

Divide:

g’( f(x) ) = 1 / f’(x)

So if it wants g’(3), you need to plug in 3 for f(x)and then, using 3 = f(x), solve for x. Then, plug in.