1. Inverse Functions
A function and its inverse function can be described as the "DO" and the "UNDO" functions. 
A function takes a starting value, performs some operation on this value, and creates an output answer. 
The inverse function takes the output answer, performs some operation on it, and arrives back at the original function's starting value.
How to create an inverse function:
Change f(x) to y
Switch x and y
Solve for y
Use inverse notation f -1(x)
#1-3 Find the algebraic inverse and graph the function and inverse on the same coordinate plane. 1.
The graph of an inverse function switches the x and y values completely.
Function graphs (x, y)
Inverse Function graphs (y, x)
It’s graph is reflected over the line y = x.

2.
NOTE: Not all functions have inverses that are functions Restrict the domain so the inverse is a function.