уравнение cos (x+pi/3) = -1

[tex]cos(x+ \frac{ \pi }{3} )=-1 \\ x+ \frac{ \pi }{3} = \pi +2k \pi \\ x= \frac{2 \pi }{3} +2k \pi \\ \\ [/tex]
Ответ :[tex] \frac{2 \pi }{3} +2kл \pi [/tex]

cos (x+π/3) = -1
x+π/3=π+2πk
x=2/3π+2πk