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

Answer:
sqrt(111)/20
Step-by-step 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