Solve for 0<=θ<π, the equation sin3θ-(sqrt3)cosθ=0 (C2)

Rearrange the equation to give sin3θ=(sqrt3)cos3θ, then divide through by cos3θ to give sin3θ/cos3θ=sqrt3. We know from our trig identities that sinx/cosx=tanx, so our equation now becomes tan3θ=sqrt3. Use your calculator to find 3θ, I got 3θ=π/3, so θ=π/9 which is within our range for θ.