(2cos6x*cosx)²=(2sin6x*cosx) :4 (cosx)² cosx не равно 0
cos²6x-sin²6x = 0
cos12x=0
12х = π/2 + πn
x= π/24 + πn/12
(2cos6x*cosx)²=(2sin6x*cosx) :4 (cosx)² cosx не равно 0
cos²6x-sin²6x = 0
cos12x=0
12х = π/2 + πn
x= π/24 + πn/12