I think what they mean is that you are supposed to "solve" for x in terms of a radian measure (as opposed to a degree measure).I attempted to "clean up" your equation.sin(x/2)=√(3)/2We are looking for the radian measure such that the sine of that measure is the same as √(3)/2. Sin(something) = √(3)/2That "something" must be either π/3 or 2π/3. Ah...but, that's not our answer. You see, "something" is really x/2, so...Either x/2 = π/3 OR x/2 = 2π/3.Solve those two equations and you will have your answer.