I have this expression:

sin^2(3x)=1/4 (reads sine squared three x equals one fourth)

when i solved it i got sinx= (plus or minus) 1/2 and the x values were from (pi)/18 to 35(pi)/18 with a total of 12 possible x values on the interval (0, 6(pi)) . Could anyone verify for me if this is correct? thanks a lot!