The Function Graphed Is of the Form Y $$y = a \sin b x \text { or } y = a \cos b x , \text { where } b > 0$$

Multiple Choice

The function graphed is of the form y $$y = a \sin b x \text { or } y = a \cos b x , \text { where } b > 0$$ Determine the equation of the graph.
-The voltage $\mathrm { E }$ in an electrical circuit is given by $\mathrm { E } = 7.7 \cos 180 \pi \mathrm { t }$ , where $\mathrm { t }$ is time measured in seconds. Find the period.

A) $90 \pi$
B) $\frac { 1 } { 90 }$
C) $\frac { \pi } { 90 }$
D) 90