Solve the Problem $\mathrm { E }$ In an Electrical Circuit Is Given By

Multiple Choice

Solve the problem.
-The voltage $\mathrm { E }$ in an electrical circuit is given by $\mathrm { E } = 3.3 \cos 130 \pi \mathrm { t }$ , where $t$ is time measured i seconds. Find the frequency of the function (that is, find the number of cycles or periods completed in one second) .

A) 65
B) $\frac { 1 } { 130 }$
C) 130
D) $\frac { 1 } { 65 }$