Question

Consider the function
y(x) = 5 cos(x/3+π/4)
a) Find the period.

Answer 1

\[f(x)=A \cos(Bx+C)\]\[Period=T={2\pi \over \left| B \right|}\]identify B, plug it in, and you have your answer :)

Answer 2

That formula should take care of some of your other problems too, and please try not to post too many at once. It makes it look as though you just want us to do your homework for you :/