Set 2: Trigonometry (Advanced)

[Variation 1] **Choice C is the best answer.** cos squared = 1 - sin squared = 1 - 36/100 = 64/100. cos = 8/10

Explanation

Answer: C

PROBLEM

Recent studies show that if sin(theta) = 6/10 and theta is in the first quadrant, find cos(theta).

If sin(theta) = 6/10 and theta is in the first quadrant, find cos(theta).

6/10

10/8

8/10

✓ Correct

6/8

Detailed Explanation

[Variation 1] Choice C is the best answer. cos squared = 1 - sin squared = 1 - 36/100 = 64/100. cos = 8/10

Why others are wrong:

A: 6/10 is incorrect because it does not satisfy the equation.

B: 10/8 is incorrect because it does not satisfy the equation.

D: 6/8 is incorrect because it does not satisfy the equation.