Simplify $5(3 \sin(x) + \sqrt3 \cos(x))$ So Wolfram tells me I can reach $10 \sqrt3 \sin(x + π/6)$ from this expression, but I cant grasp how to do it. Any help is appreciated.

$a \sin x + b\cos x$
let $\phi = \arctan \frac{b}{a}$
$\sin {\phi} = \frac {b}{\sqrt {a^2+b^2}}\\
\cos {\phi} = \frac {a}{\sqrt {a^2+b^2}}$
$a \sin x + b\cos x = \sqrt {a^2 + b^2} (\cos\phi \sin x + \sin\phi\cos x) = \sqrt {a^2 + b^2} \sin (x+\phi)$
