MTH 111 Lecture 15: Notes

Phases of sine The phase of a sine curve ) represents a particular location on the graph of the sine function . Specifically, when we have and this corresponds to the point on the graph of . Observe that each point on the graph of has different characteristics. For example, for we have sin and the values of sine are increasing, whereas at , we also have sin but the values of sine are decreasing. So each point on the graph of sine corresponds to a different “phase” of a sine curve. Complete the descriptions for each label on the graph below.

enter the expression asin(x)+15 , where asin(x) is the inverse sine function.

Proving a Double-Angle Formula: Use the Addition Formula for Sine to prove the Double-Angle Formula for Sine.