Determine the range of f(x)=sinx2+cosxf(x) = \frac{\sin x}{2 + \cos x}f(x)=2+cosxsinx.
[−1/3,1/3][-1/\sqrt{3}, 1/\sqrt{3}][−1/3,1/3]
[−1/2,1/2][-1/2, 1/2][−1/2,1/2]
[−1,1][-1, 1][−1,1]
[−1/5,1/5][-1/\sqrt{5}, 1/\sqrt{5}][−1/5,1/5]