Question

What is Half of 2pi/3

Answer 1

Answer:  The half of $\dfrac{2\pi}{3}$ is  $\dfrac{\pi}{3}.$

Step-by-step explanation:  We are given to find the half of $\dfrac{2\pi}{3}.$

Let us consider that

$x=\dfrac{2\pi}{3}.$

Then, the half of x is given by

$\dfrac{1}{2}x=\dfrac{1}{2}\times\dfrac{2\pi}{3}=\dfrac{\pi}{3}.$

Thus, the half of $\dfrac{2\pi}{3}$ is $\dfrac{\pi}{3}.$

Answer 2

 Is that cos (2pi/3) or cos^2 (pi/3) ????
1/2 of 2 =1
cos (2pi/3) = - 1/2 
cos (pi/3) = 1/2 
cos^2 (pi/3) = 1/4 

take your pick! 

pi/3 radians = 60 degrees, and cos is looking for the side adjacent to the 60 degree angle 
in a 30-60-90 triangle, the sides are in the ratio 1-sqrt(3)-2 
so cos 60 = 1/2 

2(pi/3) = 120 degrees-- the same triangle, except now, x is negative ==> cos 2pi/3 = -1/2