Sec(60°)sin(240°)+sec(60°)cos(210°) ÷ sin(210°)cos(120°)

Bab Trigonometri
Matematika SMA Kelas X

(sec 60° . sin 240° + sec 60° . cos 210°) / (sin 210° . cos 120°)
= (2 . (-1/2 √3) + 2 . (-1/2√3)) / (-1/2 . (-1/2))
= (-2√3) : 1/4
= -2√3 x 4
= -8√3

Mapel : Matematika
Kelas : X SMA
Bab : Trigonometri

Pembahasan :
Sec 60° = 1/Cos 60° = 2
Sin 240° = Sin (270 - 30)° = - 1/2 √3
Cos 210° = Cos (270 - 60)° = - 1/2 √3
Sin 210° = Sin (270 - 60)° = -1/2
Cos 120° = Cos (180 - 60)° = - 1/2

Jadi...
(Sec 60° Sin 240° + Sec 60° Cos 210°)/(Sin 210° Cos 120°)
= [2 . (-1/2 √3) + 2 . (-1/2 √3)]/[(-1/2) (-1/2)]
= [-√3 - √3]/(1/4)
= [-2√3]/(1/4)
= -8√3