Tentukan hp dari pesamaan 2 cos 2x + √3 = 0 dan 0°≤ x ≤ 720°
2cos2x+√3 = 0
cos2x =
– 2x = 150°+k.360°
x = 75°+k.180°
*k=0
x = 75°+0.180°
x = 75°
*k=1
x = 75°+1.180°
x = 255°
*k=2
x = 75°+2.180°
x = 435°
*k=3
x = 75°+3.180
x = 615°
– 2x = -150°+k.360
x = -75°+k.180
*k=0
x = -75°+0.180
x = -75° (tidak memenuhi)
*k=1
x = -75°+1.180°
x = 105°
*k=2
x = -75°+2.180°
x = 285°
*k=3
x = -75°+3.180°
x = 465°
*k=4
x = -75°+4.180°
x = 645°
HP={75°,105°,255°,285°,435°,465°,615°,645°}
Semoga membantu, jadikan yg terbaik yaa:)