Question

Find the exact value of cos a, given that sin a= 8/11 and

a is in quadrant I.
cos a= ?
(Simplify your answer. Type an exact answer, using radicals as needed.)

Answer 1

cos(a) = (√57)/11

Explanation:

cos(a) = √(1 -sin(a)²) = √(1 -(8/11)²) = √(57/121)

cos(a) = (√57)/11