nilai dari tan 165° dan sin 180° adalah..

Mapel : Matematika
Kelas : X SMA
Bab : Trigonometri

Pembahasan :
Tan 165° = Tan (180 - 15)°
Tan 165° = - Tan 15°
Tan 165° = - Tan (45 - 30)°
Tan 165° = - [(Tan 45 - Tan 30)/(1 + Tan 45 . Tan 30)]
Tan 165° = - [(1 - 1/3 √3)/(1 + 1 . 1/3 √3)
Tan 165° = - [(1 - 1/3 √3)/(1 + 1/3 √3)
Tan 165° = - [(3 - √3)/(3 + √3)]
Tan 165° = - [(3 - √3)²/(3 + √3)(3 - √3)]
Tan 165° = - [(9 - 6√3 + 3)/(9 - 3)]
Tan 165° = - [(12 - 6√3)/(6)]
Tan 165° = - [2 - √3]
Tan 165° = √3 - 2

Sin 180° = Sin (180 - 0)°
Sin 180° = Sin 0°
Sin 180° = 0