Question

If cos ∅ lies in the quadrant IV, what can be the value of cos ∅?

a) -√41/5
b) √41/5
c) -3/5
d) 3/5

Answer 1

D is the correct answer

Answer 2

3/5

Explanation:

The range of the cosine function is [-1, 1]. Since √41/5 is greater than 1, we eliminate answers a) and b) immediately.

If this angle lies in Quadrant IV, the "adjacent side" is positive. Thus, the cosine of this angle must be 3/5.