Question

As respostas são:

A) √3/2
B)-√3/2
C)√2/2
D)-√2/2
E) 1

Answer 1

$\sin(x) = \frac{1}{2} \\ { \sin}^{2} x = {( \frac{1}{2} )}^{2} = \frac{1}{4}$

${ \cos }^{2}x = \frac{3}{4} \\ \cos(x) = - \sqrt{ \frac{3}{4} } = - \frac{ \sqrt{3} }{2}$

Alternativa b