himpunan penyelesaian persamaan 1 + 2 cos (2x - 10) = 2 pada interval [tex]0 \leqslant x \leqslant 360[/tex]

1 + 2 cos (2x - 10) = 2
2 cos (2x - 10) = 2 - 1
2cos (2x - 10) = 1
cos (2x -10) = 1/2
cos (2x -10) = cos 60°, 300°
2x -10 = 60
2x = 70 + k.360
x = 35 + k.180
k = 0 => x = 35
k = 1 => x = 215
k = 2 => x = 365 ( tidak dipakai karena di luar interval)
2x -10 = 300
2x = 310 + k.360
x = 155 + k.180
k =0, => x = 155
k = 1 => x = 335
k = 2 => x = 515 ( tidak dipakai karena di luar interval)
HP = { 35, 155, 215, 335 }