# How do you find the value of cos 8(pi) using the graph?

$\textcolor{b l u e}{1}$
$8 \pi$ is 4 complete revolutions around the unit circle. If we start at $0$ and cycle 4 times around the unit circle, we are back to where we started. i.e. $0$.
$\cos \left(8 \pi\right) = \cos \left(0\right) = \textcolor{b l u e}{1}$