Soal MTK tingkat SMA

Jawab:

HP { 0, phi/3, 5phi/3, 2phi}

Penjelasan dengan langkah-langkah:

2 cos² X – 3 cos X = -1

misal cos x = p

2 p^2 – 3p = 1

p = 1 p = 1/2

cos x = 1

cos x = cos 360

x = 360 + k.360

k = 0 , x = 360 atau 2phi

x = -360 + k.360

k= 1 , x = 0

cos x = 1/2

cos x = cos 60

x = 60 + k 360

k = 0 , x = 60 atau phi/3

x = -60 + k 360

k = 1, x = 300 atau 5phi/3

HP { 0, phi/3, 5phi/3, 2phi}