Question

cos x/2=sqrt 2/2

Answer 1

I'll tell you about one value because this is a very basic trigonometry question.

cos x/2 = sqrt 2/2 = 1/ sqrt 2 = cos 45

Equate x/2 = 45
As their cosines are equal! :D

Understood? :)

Answer 2

thanks

Answer 3

:)

Answer 4

use the identity :
cos(x/2) = sqrt( (cosx + 1)/2 )

Answer 5

Another angle is cos -45, which is in the fourth quadrant.

Answer 6

@RadEn , I don't think we NEED to use that. When we are given the direct trigonometric ratios.

Answer 7

just alternative