Question

If sinθ=34
and π2<θ<π
, find cosθ
.(1 point)
cosθ=

Answer 1

Assuming you mean sin θ = 3/4 and π/2 < θ < π (second quadrant), cos θ is negative:
cos θ = −√(1 − sin^2θ) = −√(1 − (3/4)^2) = −√(7/16) = −√7/4.