State the amplitude, period, and phase shift of the function y=-3cos(3x+ (3pi/2))

Question

Amplitude: 3
Period: 2pi/3
Phase Shift: -pi/2

Am I right?

Answer 1

yes

Although I would personally like to see it written as
y = -3cos 3(x + pi/2)

that way the phase shift sort of hits you in the face.