Question

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

Answer 1

Answer:

$\frac{\sqrt{7} }{4}$

Step-by-step explanation:

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

by pythagoras' theorem, adjacent length = $\sqrt{7}$

thus cos theta = adjacent/hypotenuse = $\frac{\sqrt{7} }{4}$

Answer 2

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