Section 3.5 Circular Functions We know what we are, but know not what we may be. - William Shakespeare

Definition Circular Functions If (u,v) is the terminal point of an arc of length x in standard position on a unit circle, then the circular functions of x are defined as follows: (cos x, sin x) = (u,v) v = sin x u = cos x x radians arc = x

Example Plot the graph of on your grapher, in radian mode. Find the period graphically and algebraically. Period: 1.2566

1 Determine the sinusoidal axis. y = ?

2 Determine the amplitude

3 Determine the period.

4 Determine the horizontal dilation A B C D 10

5 Determine "B" A B C D 10

6 Determine the phase displacement for cosine.

7 Determine the equation for the sinusoid. A B C D E F

8 Match the graph of A B C D E