Роман Ягодин 2cos3x=√3cosx+sinx, cos3x=(√3/2)cosx+(1/2)sinx, cos3x=cos(x-π/6); cos3x-cos(x-π/6)=0; -2sin(2x-π/12)sin(x+π/12)=0; 1) sin(2x-π/12)=0, 2x-π/12=πk, x₁=π/24+πk/2. 2) sin(x+π/12)=0; x+π/12=πn, x₂=-π/12+πn/2