Answer the following with reference to the unit circle.

MATHEMATICS · Multi-part · AP · AP Precalculus · Trigonometric and Polar Functions · Trigonometric and Polar Functions

Problem

Answer the following with reference to the unit circle. (a) State the meaning of the term "unit circle" used in trigonometry. (b) For any real angle

\theta

, write the coordinates of the corresponding point on the unit circle in terms of the sine and cosine of

\theta

. (c) List the exact coordinates of the points on the unit circle corresponding to the angles

0^\circ,\;30^\circ,\;45^\circ,\;60^\circ,\;90^\circ

and

180^\circ

. Write each coordinate pair in the form

(\cos \theta,\sin \theta)