i only need help with number 20 Solve each equation on the i

?i only need help with number 20

Solve each equation on the interval 0 lessthanorequalto theta lessthanorequalto 2pi cos theta = 1/2 tan (0theta) = 0

Solution

given tan2=0

so tan(2) = 0
2= 0, ±, ±2, ±3, ...
= 0, ±/2, ±, ±3/2, ...
or = n/2 for any integer n

0<<2pi

solution set is : {0,/2,,3/2,2 }