Jika tan (x) = 5/12 di kuadran ketiga, cari rasio trigonometri lainnya
tan x = 12/5, x di kuadran III
Di kuadran ketiga, tan x dan cot x positif. sin x, cos x, sec x, cosec x negatif.
Dengan menggunakan rumus,
ranjang x = 1/tan x
= 1/(12/5)
= 5/12
cosec x = – √ (1 + cot 2 x)
= – √ (1 + (12/5) 2 )
= – √ (25 + 144) / 25
= – √ (169/25)
= -13/5
sin x = 1/cosec x
= 1/(-13/5)
= -5/13
cos x = – √ (1 – sin 2 x)
= – √ (1 – (-5/13) 2 )
= – (169-25)/169
= – (144/169)
= -12/13
detik x = 1/cos x
= 1/(-12/13)
= -13/12
sin x = -5/13, cos x = -12/13, cot x = 5/12, cosec x = -13/5, sec x = -13/12
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