Express $9$ $\cos \theta + 5$ $\sin \theta$ in the form of $R \sin(\theta + \alpha)$ where&n

Question

Express $9$ $\cos \theta + 5$ $\sin \theta$ in the form of $R \sin(\theta + \alpha)$ where $\alpha$ is in radians.

Accepted Answer

$\sqrt{106}\sin(\theta+1.06)$

Trigonometry - R-Formula and Trigonometric Extrema