To find cos x, we must first find sin x. sin x = opp / hyp = 32/58.
Note the identity (sin x)^2 + (cos x)^2 = 1. Since we want cos x, solve this for
(cos x)^2: (cos x)^2 = 1 - (sin x)^2.
Here, (cos x)^2 = 1 - (32/58)^2 =
However, it'd be much easier to find the length of the 3rd side using the Pythagorean Theorem:
58^2 = 32^2 - x^2 => 2340 = x^2 and x = +48.37.
If we round this off, we get cos x = adj / hyp = 48/58. This is Answer A.