Question

What's the phase shift of "y = sin(3x - pi)"?

Is it pi/3 to the right?

Answer 1

yes it is

Answer 2

I agree. Relative to the curve y = sin 3x, and assuming you are plotting y vs x, sin(3x - pi)is shifted pi/3 to the right. In other words, when x is increased by pi/3, the argument (3x-pi)of the y = sin(3x - pi)function has the same value as 3x of the sin 3x function.