Question

O valor de COS² X para X = 2$\pi$/3 é:

Answer 1

Boa noite

cos²(x) 

2pi/3 = 2*180/3 = 120°

cos(120) = - 1/2 

cos²(120) = (-1/2)² = 1/4 

Answer 2

$\mathsf{cos(x)\bigg|_{x=\frac{2\pi}{3}}=cos(\dfrac{2\pi}{3})=-\dfrac{1}{2}}$

$\boxed{\boxed{\boxed{\mathsf{{cos}^{2}(x)={(-\dfrac{1}{2})}^{2}=\dfrac{1}{4}}}}}$