Trig question eq in the form y = sin k x

[Matt1234]

1. The problem statement, all variables and given/known data

http://img62.imageshack.us/img62/7677/30639229.jpg

2. Relevant equations

y = sin k x



3. The attempt at a solution

Looking for help with part 12b in particular so i can try 13c

Im not quite sure how the coefficent of x (K) in the function y=sin kx relate to peroid and frequency. I know that if k is less then 1 the graph is stretched horizontally and if k > 1 its compressed horizontally but i cant come up with the equation.

[rock.freak667]

Periodic functions follow the form

y=Acos(ωt)

OR

y=Asin(ωt)


ω is the angular frequency. (In your question, A=1)

[Matt1234]

i got it the formula i could not recall was that period = 2Pi / K (constant in my question)
thanks for your help sir!