### Home > APCALC > Chapter 6 > Lesson 6.4.2 > Problem 6-142

6-142.

Recall that . Use the formula for the derivative of an inverse to compute

is another way of saying that

*and*

*are inverse functions.*

Inverse functions have reciprocal derivatives at their corresponding

If has the coordinate point

and is the inverse of

*, then*

Let and

*.*

First find

*_____.*

To find , take the reciprocal of

*x*-value.

Now evaluate when

*.*