FUNCTIONS Inverse Functions (Page 9 of 9)

We can graphically test if two functions are inverses by graphing both composition functions. If their graphs are identical to the graph of the identity function y = x, this would be a convincing argument.

Let's change the graph style of Y4 to be a thick line (so we can differentiate the graphs), and then graph both compositions. The graph style icons are located to the far left of the function definition in the function editor.

Y= key.
Left arrow key. Left arrow key. Down arrow key. Down arrow key. Down arrow key. ENTER key.

ZOOM key. 6: menu selection.

 Calculator screen image. Calculator screen image.

The graphs (which overlap) seem to be identical to the graph of y = x. Based on the numerical and graphical evidence, the functions do appear to be inverses.
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