How to draw the graph of y = sin(x + pi/4) and y = sin(x - pi/2)

This lesson shows how to draw the graph of y = sin (x + pi/4) and y = sin (x - pi/2). Reader needs to understand how to draw the graph of y = sin(x). In which case should shift the graph
of y = sin(x) left certain units and in which case should shift the graph of y = sin(x) right certain units. Understand the standard sine function y = A sin (Bx + C). What does these
parameter A, B and C represent.