= ---> (divide bith sides by 2) ---> = . (1) Notice that = and = . Therefore, you can rewrite (1) as = . (2) Now apply the addition formula for sine = . You will get instead of (2) = . Then pi/6 + x/2 = , k = 0, +/-1, +/-2, . . . Hence x = . To get the given interval for x, take k = 1 and k = 2. You will have two solutions x = = and x = = . Answer. There are two solutions in the given interval. They are x = and x = .