What is the Frequency of an Alternating Current with a Sin Curve?

[JBemp]

Homework Statement

what is the frequency F for the alterating current
U(T)=15cos(314t) A

Homework Equations

Am really new at this kind of problem but i think 314 is how many times the current rotates or fluxuates in 1 period so the F has to be the distance between waves?

The Attempt at a Solution

15cos(314T)

314/2pi i get 493.23 but i know that's wrong

 

[arunbg]

Are you sure 314/(2pi) is 493.23? Check with your calculator properly

 

[fikus]

$$U\propto cos(\omega t) ~~~~ \omega = 2\pi \nu$$

So you should divide 314 with 2pi, not divide 314 with 2 and then multiply with pi.

 

[JBemp]

ok i see what i did worng forgot the darn ( ) on the calc. man these ( ) always screw me.

thank you both