Question 886928
Find two solutions of the equation. Give your answers in degrees and radians. 
(a) cos theta = sqrt2/2 (b) cos theta = -sqrt2/2 
***
In the first case(a), theta is in quadrant I or IV, in which cos>0.
So, theta=45˚and π/4, or 315˚and 7π/4
..
In the second case(b), theta is in quadrant II or III, in which cos<0.
So, theta=135&#730;and 3&#960;/4, or 225&#730;and 5&#960;/4