Question 11
**(b)** Hence solve the equation $5\sin\left(2\theta+\frac{1}{6}\pi\right)-4\cos 2\theta = \sqrt{7}$ for $0 \le \theta \le \pi$. Give your answers correct to 2 decimal places.
(In part (a) you found $5\sin\left(x+\frac{1}{6}\pi\right)-4\cos x = \sqrt{21}\sin(x-\alpha)$ with $\alpha = 0.333$.)
(In part (a) you found $5\sin\left(x+\frac{1}{6}\pi\right)-4\cos x = \sqrt{21}\sin(x-\alpha)$ with $\alpha = 0.333$.)
