Answer the following questions with reference to the unit circle.

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

Problem

Answer the following questions with reference to the unit circle. (i) Explain what is meant by the “terminal point” corresponding to an angle θ\theta on the unit circle. (ii) Describe how the signs of sin⁡θ\sin\theta and cos⁡θ\cos\theta are determined from the position of the terminal point in the four quadrants. (iii) Without using any numerical calculation, justify that sin⁡150∘>0\sin150^{\circ}>0 while cos⁡150∘<0\cos150^{\circ}<0.

Related theory

Browse the problem library