Phase Shift
The next transformation that you will learn and implement is called a phase shift. A horizontal translation, or shift, of a trigonometric function is called a phase shift. This means that the graph of your function will be moved to the left or right of the basic function.
How do you find the phase shift? Look at the following equation:
To find the zeros:
Asin(kx - c) = 0
You know that sin 0 = 0, so then kx - c = 0.
Solve for x:
This is the definition of phase shift: 
.
If c > 0, the graph shifts to the right.
If c < 0, the graph shifts to the left.
If c = 0, the graph does not shift.