-sinx+cosx=1 untuk -2π≤x≤2π adalah

-sin x + cos x = 1
kuadratkan kedua ruas
(-sin x + cos x)² = 1²
sin²x + cos²x - 2.sin x cos x = 1
1 - 2.sin x cos x = 1
-2.sin x cos x = 0
2.sin x cos x = 0
sin 2x = 0
sin 2x = sin -4π
2x = -4π
x = -4π/2 = -2π
sin 2x = sin -2π
2x = -2π
x = -π
sin 2x = sin -π
2x = -π
x = -½π
sin 2x = sin 0
2x = 0
x = 0
sin 2x = sin π
2x = π
x = ½π
sin 2x = sin 2π
2x = 2π
x = π
sin 2x = sin 4π
2x = 4π
x = 2π
hp {-2π,-π,-½π,0,½π,π,2π}