помогите решить уравнение cos(π/3+5x)=-1/2

π/3+5*x1=π/2+π/6+2*π*N⇒x1=(π/2+π/6-π/3+2*π*N)/5=π/15+0,4*π*N

π/3+5*x2=1,5*π-π/6+2*π*N⇒x2=(1,5*π-π/6-π/3+2*π*N)/5=π/5+0,4*π*N