So sinx = 0 is true when x = 0 and pi and all the angles coterminal with these points. Thus, the answer is x = pi*n, (where n is some integer)
sinx = 1/2 is true when x = pi/6 and 5pi/6 and the angles coterminal with these points. Thus, the answer is x = pi/6 + 2pi*n (where n is some integer) and x = 5pi/6 + 2pi*n (where n is some integer)