Question

Modeling a cosine function [see attachment]
What is the period and what is b

Answer 1

it takes 1 second one way, and 1 second to go back to its original position, thus the period is 2 seconds.

$\bf \stackrel{\textit{period of cosine}}{\cfrac{2\pi }{b}}\implies 2\implies \cfrac{2\pi }{b}=2\implies \cfrac{2\pi }{2}=b\implies \pi =b\\\\ -------------------------------\\\\ d=6cos(\pi t)$

Answer 2

The answer is b to let you know