If θ is in quadrant iv and sinθ = -1/2, then cosθ

Solution : Quadrant IV ranges from 270 deg to 360 deg Also sinθ = - value & cosθ= + value in IV quadrant Here, sinθ = -1/2, we know sin30=1/2 this gives, θ = 330deg as sinθ = sin(360-θ) Hence, cosθ=cos330=cos(360-30)=cos30 cos30 = âš3/2