Question

1 задание, 1 пример!!!!!!!

Answer 1

$cos5x+cosx=0\ \ 2cos(frac{5x+x}{2} )*cos(frac{5x-x}{2} )=2cos3x*cos2x=0\ \ 1аcos3x=0\ 3x=frac{pi}{2} +pi n\ x_1=frac{pi}{6} +frac{pi n}{3} \ \ 2аcos2x=0\ 2x=frac{pi}{2} +pi n\ x_2=frac{pi}{4} +frac{pi n}{2}$