1. Finding the Inverse of a Function Algebraically
Module 1 Day 6
Finding the Inverse of a Function Algebraically

2. Finding the Inverse of a Function
Finding an inverse from ordered pairs
1. Switch the x and y.
2. Determine if the relation is still a function by seeing if any of
the domains (x-values) are the same.
Finding an inverse from a function
1. The f(x) can be changed to a y, since they are equivalent.
2. Switch the x and y.
3. Solve for y.

3. Examples: Find the inverses
1. f(x) = 4x – 9
2. f(x) = 3𝑥 2 +7
3. f(x) = 2+ 3 𝑥−7

4. Determining if two functions are inverses?
Are two functions inverses?
1. Complete the composites of the functions. F[g(x)] and G[f(x)].
2. Both answers should result in a solution of x for them to be inverses
3. If either of the composites doesn’t give a value of x,then the functions are not inverses

5. Examples: Prove whether or not the following functions are inverses
f(x) = 3𝑥 2 +7 and g(x) = 𝑥−7 3
f(x) = 5x-9 and g(x) = 𝑥+9 5