Question

How do you find θ, if `0 < θ < 360` and `cos theta = -1/sqrt2` and theta in in Qii?

Answer 1

Find x knowing `cos x = - 1/sqrt2`

Ans: `(3pi)/4`

Explanation:

Trig table gives -> `cos x = - 1/sqrt2 = - sqrt2/2` --> `x = (3pi)/4` or 135 deg