Question

Помогите решить, тригонометрия.

Answer 1

$frac{cos alpha +cos3 alpha }{cos3 alpha *cos alpha } * frac{cos alpha *cos2 alpha -sin alpha *sin2 alpha }{sin alpha *cos alpha }$
=$frac{cos alpha +cos3 alpha }{cos3 alpha *cos alpha } * frac{cos3 alpha }{ysin alpha cos alpha }$
=$frac{cos alpha +cos3 alpha }{cos^{2} alpha *sin alpha }$

2) $frac{sin4 alpha *cos alpha -cos4 alpha *sin alpha }{sin alpha *cos alpha } * frac{sin3 alpha +sin alpha }{sin3 alpha *cos alpha }$ 
=$frac{sin3 alpha }{sin alpha *cos alpha } * frac{sin alpha +sin3 alpha }{sin3 alpha *cos alpha }$    
=$frac{sin3 alpha +sin alpha }{sin alpha *cos ^{2} alpha }$