] as y

] as y = sin is periodic with period p . The graph of sine function is shown in Fig. . . The portion of the curve corresponding to to p is called a cycle . Its amplitude is . Note Observe that sin x ≥ for ≤ π , which corresponds to the values of the sine function in quadrants I and II and sin x < for π < < , which corresponds to the values of the sine function in quadrants III and IV. Fig. . Fig. . π π π π π π O x x ∈ sin ,  period - O = sin [ , ] in π - amplitude π π Inverse - -