Sin functions are functions that are essentially squiggles that repeat over and over. 
In order to move the graph or change the amplitude, I can do the following. In order to move the graph, I can use the equation y = sin(x – the shift in x) + the shift in y. This will move the equation while still keeping the same exact shape. If I wanted to change the amplitude, I could use y = (amplitude)sin(x).
The Book of Moorman 