Question

PRECALC!!! The angle θ(1) is located in quadrant I, and sin(θ1)= 17/20. what is the value of cos(θ1)

Answer 1

sqrt(111)/20

Explanation:

cos²(theta) = 1 - sin²(theta)

= 1 - (17/20)²

cos²(theta) = 111/400

Since it's in the first quadrant, take the positive root

cos(theta) = sqrt(111)/20

sqrt: square root