Question

cos5x+cos3x+2cosx=0 решите плиз срочно надо

Answer 1

2cos4x* cosx +2cosx = 0
2cosx(cos4x +1) = 0
cosx(cos4x + 1) = 0
1) cosx = 0
$x = frac{ pi }{2} + pi n$
2) cos4x = -1
$4x = pi +2 pi k$
$x = frac{ pi }{4} + frac{ pi k}{2}$

Answer 2

спасибо большое)