1. Chapter 1: Lesson 1.9 Inverse Functions
Finding the inverse of a function
Switch x → y and y → x
Solve for y

2. Verifying Inverse Functions Algebraically

3. Verifying Inverse Functions Graphically
2 functions are inverses of each other if the 2 functions are symmetric about the line y = x. See page 86.
Another way to check is that if (x, y) exists on f(x), then (y, x) should exist on the inverse function.
See #18 on page 90

4. Horizontal Line Test
The inverse of a relation is a function if no horizontal line intersects the relation at more than 1 point.
Determine whether the function has an inverse function. If it does, then find the inverse function.