Question

If sin theta = 3/4 and is in the first quadrant, then cos theta

Answer 1

sin(θ)=3/4
α=sin^-1 (3/4)
= 0.84806207898
since it is in the first quadrant
θ=0.84806207898
thus cos(θ)=cos(0.84806207898)
= 0.66143782777

Answer 2

`(√(7) )/(4)`

Explanation:

since sin theta = 3/4, opposite length = 3 units and hypotenuse length = 4 units

by pythagoras' theorem, adjacent length =
`√(7)`

thus cos theta = adjacent/hypotenuse =
`(√(7) )/(4)`