What are Two of the solutions of cos(x/2)= -√2/2?

1 Answer
Apr 30, 2018

Within one period (0 < x/2 < 2pi):

x=(3pi)/2, (5pi)/2

Explanation:

.

cos(x/2)=-sqrt2/2

Negative cosine values indicate that the angle is either in quadrant II or quadrant III.

From the unit circle:

x/2=(3pi)/4, (5pi)/4

x=(3pi)/2, (5pi)/2