Find the solutions of the equation that are in the interval

Find the solutions of the equation that are in the interval [0, 2). (Enter your answers as a comma-separated list. If there is no solution, enter NO SOLUTION.) 5 20 cos2 t = 0

Solution

Given equation

5 20 cos2 t = 0

5 = 20 cos2 t

5 /20 = cos2 t

0.25 = cos2t

2t = 1.318 radians

t = 0.659 radians