trig
posted by kikine .
Given the function y = 3cos(3x + pi), identify:
Amplitude (if applicable, give the answer in fractional form)
Period (in radians as a multiple of pi  note: do not write "rad" or "radians" in your answer)
Phase Shift (if the shift is right, enter + and if to the left, enter  before the number; if none, enter the number zero)

y = 3cos(3x + pi)
y = 3cos 3(x + π/3)
amplitude : 3
period = 2π/3
phase shift: π/3 to the left