Mahasiswa/Alumni Universitas Jember
Dijawab 17 menit yang lalu
Daftar Isi
Jawaban yang benar adalah – 2/3 √3.
Ingat konsep berikut ini:
cosec x = 1/sin x
sin (-x) = – sin x
cosec (-120°) = – 1/sin (120)°
cosec (-120°) = -1/sin(180°-60°)
cosec (-120°) = -1/sin 60°
cosec (-120°) = -1/(1/2 √3)
cosec (-120°) = – 2/√3
cosec (-120°) = – 2/√3 x √3/√3
cosec (-120°) = – 2/3 √3
Jadi, cosec (-120°) adalah – 2/3 √3.
cosec x = 1/sin x
sin (-x) = – sin x
cosec (-120°) = -1/sin(180°-60°)
cosec (-120°) = -1/sin 60°
cosec (-120°) = -1/(1/2 √3)
cosec (-120°) = – 2/√3
cosec (-120°) = – 2/√3 x √3/√3
cosec (-120°) = – 2/3 √3
