matematika wajib kelas x bab trigonometri

a)
panjang sisi miring = √(12² + 9²) = √(144 + 81) = √225 = 15

sin a = de/mi = 12/15
cos a = sa/mi = 9/15
tan a = de/sa = 12/9
cosec a = 1/sina = 15/12
sec a = 1/cosa = 15/9
cotan a = 1/tana = 9/12

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b.
panjang sisi miring = √((-9)²+2²) = √(81 + 4) = √85

sin a = de/mi = 9/√85
cos a = sa/mi = 2/√85
tan a = de/sa = 9/2
cosec a = √85/9
sec a = √85/2
cotan a = 2/9

Itu nilai negatifnya jadi positif karena sudutnya lancip, nilai trigonometrinya positif semua.