x = 2п/3 - y
cos[6(2п/3 - y)] + cos6y = 2
cos(4п - 6y) + cos6y = 2
cos6y + cos6y = 2
2cos6y = 2
cos6y = 1
6y = 2пk
y = пk/3
x = 2п/3 - y = 2п/3 - пk/3
x = 2п/3 - y
cos[6(2п/3 - y)] + cos6y = 2
cos(4п - 6y) + cos6y = 2
cos6y + cos6y = 2
2cos6y = 2
cos6y = 1
6y = 2пk
y = пk/3
x = 2п/3 - y = 2п/3 - пk/3