Question

im not sure if my answers are correct... please help!

Find the phase shift of the function y = 5cos(2x +pi/2 ).


left pi/2 <<< i chose this!
right pi/2
left pi/4
right pi/4

Which of the following functions has a maximum y value of 4?

y = 4cosx << i chose this!
y = cos4x
y = cosx + 4
y = cos(x + 4)

Find the period of the function y = sin(2x + 1.5).

pi/2
π << i chose this!
3pi/2
2π