Trigonometry
posted by Lauren .
4. Write the equation of the cosine function with an amplitude of 1/3, a period of 2pi, and a phase shift of 3pi/2.
I got 1/3COS(1/2x3pi), but I really do not think that is correct D: any tips or advice?

why the half? cosx already has a period of 2pi.
1/3 cos(x3pi/2)