Given that angle A is an angle found in the first Quadrant. What is the measure (in radians) of another angle that has the same cosine value as angle A?

A)

π

2

+ A

B) π - A

C) π + A

D) 2π - A

E) 2Aπ

D)

Explanation:

We have been given that angle A is an angle found in the first Quadrant. We are asked to find the measure (in radians) of another angle that has the same cosine value as angle A.

We will use unit circle to answer our given problem.

On unit circle point represents .

We know that cosine is positive in 1st quadrant and 4th quadrant.

To find the another angle, which has same cosine value, we need to subtract measure of angle A from 2 pi.

Therefore, the angle has the same cosine value as angle A.