Chapter 4 - Section 4.5 - Finding an Equation from Its Graph - 4.5 Problem Set - Page 238: 10

$\cos x$

The graph has y = 1 at $x = 0, 2\pi$ y = 0, at x = $\frac{\pi}{2}$ Period is $2\pi$ Amplitude is 1 No vertical shift found as average of maximum and minimum is 0 Given that graph is of trigonometric function So it clearly is graph of $\cos x$