Page 14 - E-MODUL INTERAKTIF ATURAN SINUS COSINUS (KHOIRIANA NUR R)

E-Modul Matematika Aturan Sinus dan Cosinus

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CATATAN

Definisi Perbandingan Trigonometri Segitiga Siku-Siku
A

sin = cosec =

cos = sec =

tan = cotan =
B C
Gambar 1.1

SUDUT BERELASI
cos = KUADRAN I

sin(90° − ) = cos sin(180° − ) = sin
KUADRAN II

tan =
cos(90° − ) = sin cos(180° − ) = −cos

tan(90° − ) = cotan tan(180° − ) = −tan KUADRAN III

cosec(90° − ) = sec cosec(180° − ) = cosec KUADRAN IV

sec(90° − ) = sec(180° − ) = −

SUDUT NEGATIF
cotan(90° − ) = tan cotan(180° − ) = −cotan

sin(270° − ) = −cos sin(360° − ) = −sin sin(− ) = − sin

cos(270° − ) = −sin cos(360° − ) = cos cos(− ) = cos

tan(270° − ) = cotan tan(360° − ) = −tan tan(− ) = −tan

cosec(270° − ) = −sec cosec(360° − ) = −cosec cosec(− ) = −cosec

sec(270° − ) = − sec(360° − ) = sec(− ) =

cotan(270° − ) = tan cotan(360° − ) = −cotan cotan(− ) = −cotan

Sudut & Kuadran Identitas Trigonometri

 Kuadran I = 0°< < 90° 1 1
All (sin, cos, tan, coosec, sin = ↔ cosec =

sec, cotan) → POSITIF (+) 1 1
 Kuadran II = 90°< < cos = ↔sec =
180°
1 putaran = 360° 1 1
Sin, cosec → POSITIF (+) tan = ↔cotan =
180°  Kuadran III = 180°< <
1 radian =
270°
Tan, cotan → POSITIF (+) 2 2
+ = 1
 Kuadran IV = 270°< <
2
2
360° 1 + =
Cos, sec → POSITIF (+) 1 + =
2
2