Find exact radian solutions of the equation that are in the

Find exact radian solutions of the equation that are in the interval [0, 2(pi))

Find exact radian solutions of the equation that are in the interval [0, 2(pi)) cos (3 theta - pi/4) = 1

Solution

cos(3 theta-pi/4)=1

3 theta-pi/4=cos^-11

3theta=pi/4, 9pi/4,17pi/4

theta=pi/12, 3pi/4, 17pi/12