Can someone explain how to find the period of a trig function? Example problem: y=2cos(x/3)

Question

turingtest · Answer

For trig equations of the form$$A\cos(Bx+C)$$the period T is given by$$T=\frac{2\pi}{|B|}$$identify your B and plug it into the formula for the period.

lukecrayonz · Answer

So your b would be what for that problem?

turingtest · Answer

I'm not going to tell you straight away.
Ask yourself:
What is A in this formula?
What is C?
When you identify those, the remaining number will be B. It should be obvious when you figure it out.

turingtest · Answer

want a hint?

lukecrayonz · Answer

Yes D:

lukecrayonz · Answer

A is 2 haha, i have no idea since its a fraction :S

turingtest · Answer

$$A\cos(Bx+C)$$Yours can be written as
$$2\cos(\frac{1}{3}x+0)$$Does that make it more clear?

lukecrayonz · Answer

Yes :P Now i feel stupid.

turingtest · Answer

Please don't. New concepts are like that. Happens to me almost every day ;)