### Home > CALC > Chapter 2 > Lesson 2.1.3 > Problem 2-38

2-38.

Recall your answer to problem 2-27.

The vertical line test: *f* is a function if each *x*-value has exactly one out *y*-value.

The horizontal line test: The inverse of *f* is a function if each *y*-value has exactly one *x*-value.

Consider common even and odd functions:

common even functions: *x*^{2}, *x*^{4}, *x*^{6}, |*x*|, cos*x*

common odd functions: *x*, *x*^{3}, *x*^{5}, sin*x*

Use the eTool below to explore.

Click on the link to the right to view the full version of the eTool. Draw Inverse eTool