Решите уравнение 7cos (2x-π/3) = -3.5
7cos (2x-π/3) = -3.5|:7 cos (2x-π/3) = -1/2 2x-π/3=+-(π-arccos1/2)+2πn, n∈Z 2x-π/3=+-2π/3+2πn, n∈Z 2x=+-2π/3+π/3+2πn, n∈Z |:2 x=+-π/3+π/6+πn, n∈Z x1=π/2+πn, n∈Z x2=-π/6+πn, n∈Z