The phase shift is the amount that the graph is shifted to the right or to the left. The graph is shifted when a constant is added to or subtracted from the angle. The phase shift for y = A sin (Bx + c) or y = A cos (Bx + c) is found when Bx + c = 0. "Phase shift" is where the cycle starts and "phase shift + period" is where that cycle ends.
y = sin (2x + /2)
To find the phase shift set: