Solve the problem.
-The height of the water, $\mathrm { H }$, in feet, at a boat dock t hours after $7 \mathrm {~A} . \mathrm { M }$ is given by $\mathrm { E } = 17 + 5.8 \cos \frac { \pi } { 85 } \mathrm { t }$, where $t$ is time measured in seconds. Find the period.
A) 170
B) $\frac { \pi } { 170 }$
C) $\frac { 1 } { 170 }$
D) $170 \pi$

Question

Quizplus · Accepted Answer

The period of a cosine function of the form $y = a \cos(bx)$ is given by $\frac{2\pi}{|b|}$. In this case, $b = \frac{\pi}{85}$, so the period is $\frac{2\pi}{\frac{\pi}{85}} = 170$ seconds.

Solve the Problem H\mathrm { H }H , in Feet, at a Boat Dock T Hours After

Solve the Problem $\mathrm { H }$ , in Feet, at a Boat Dock T Hours After