Question

given that cos theta= sqrt3/2 of a triangle on the unit circle what is the sine ratio of the same triangle

Answer 1

Use sin^2θ + cos^2θ = 1. With cosθ = √3/2,

sin^2θ = 1 − (√3/2)^2 = 1 − 3/4 = 1/4,

so sinθ = ±1/2.

If θ is the acute angle (first quadrant, as in a standard triangle), sinθ = 1/2.