Question 384110
determine the amplitude and period and phase shift of each function. 
Then graph one period of the function. 

y= 
Amp = 1, period = pi radians, shift = pi/2 to the right.
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y= –3 cos 1/3x 
Assuming you mean -3cos(x/3):
Amp = 3, period = 6pi, shift = 0