Question

Prove: 3cosx-4sinx=2cosx+sinx

Answer 1

$3 \cos( \alpha ) - 4 \sin( \alpha ) = 2 \cos( \alpha ) + \sin\alpha \\ \cos( \alpha ) = 5sin \alpha \\ \tan( \alpha ) = \frac{1}{5} \\ \alpha = \tan{}^{ - 1} ( \frac{1}{5} )$