This lesson shows how to draw the graph of y = sin(x/2). The period of y = sin(x/2) is 4pi. half period is 2pi. quarter period is pi. Three-quarter period is 3pi. when x = 0, y = 0, which is the intercept point. When x is the half period, y = 0. (the point which make y = 0 is the intercept point.) When x is the quater period, y is the maximum which is positive one. When x is the three-quarter period, y is the minimum which is negative one. When x is full period, y is back to 0 which is the start point. The graph of y = six(x/2) will repeat in every 4pi interval. Note the difference of the graph of y = sin x, y = sin2x and y = sin(1/2)x.