y = 2π - x
cos(x) + cos(2π - x) = 1
2 * cos(x) = 1
cos(x) = 1/2
x = ±π/3 + 2*π*n
y = 2*π - (±π/3 + 2*π*n)
y = 2π - x
cos(x) + cos(2π - x) = 1
2 * cos(x) = 1
cos(x) = 1/2
x = ±π/3 + 2*π*n
y = 2*π - (±π/3 + 2*π*n)