Find the intervals on which sinx-(root3)(cosx) is increasing and decreasing

Answer 1

y = sinx - 3^0.5 * (cosx)
dy/dx = cos x + 0.5 * 1/ (3^0.5) sin x
= cos x + 0.29 sin x
where is that zero? where is it plus? where is it minus?

Answer 2

y = sinx - √3 cosx
y' = cosx + √3 sinx = 2sin(x + π/6)