Inverse Functions • The domain of the inverse is the range of the original function • The range of the inverse is the domain of the original function • Switching x and y
To determine whether the inverse is a function… • Switch x and y values and determine whether the domain of inverse is paired with only one value in the range (domain can not repeat)
Determining whether the inverse is a function from the graph of the original • You do the vertical line test to determine whether the graph represents a function • To determine whether its inverse would be a function, then you would do a horizontal line test
Finding the Inverse of a Relation What is the inverse of relation s? Relation s X Y 0 -1 2 0 3 2 4 3
To find the inverse of a function • • 1. 2. 3. 4. Notation: f -1(x)= Steps: Replace f(x) with y Switch the x and y variable Solve for y Replace y with f -1(x)=
Find the following
Find the following
Things to Remember! •
Inverse Sine Function The horizontal line test shows that the sine function is not one-to-one and has no inverse function.
The Restricted Domain •
Graph the Inverse Sine • x y -1 x -1 y -. 707 0 0. 707 1 1
Graph of Inverse Sine x -1 y 0. 707 1
Inverse Cosine Function • As with the sine, the domain must again be restricted. For cosine we restrict to
Graph the Inverse Cosine • x 0 y 1 x 1 . 707 0 0 -. 707 -1 -1 y 0
Graph of Inverse Cosine x 1. 707 0 -. 707 -1 y 0
Inverse Tangent Function •
Graph the Inverse Tangent x y und x und y -1 0 0 1 1 und