jika (A-B) = 30derajat dan sin A cos B =2/3 dgn A dan B sudut lancip maka nilai sin (A+B) =...... makasih byk

2 sin A cos B = sin (A + B) + sin (A - B)
2 . (2/3) = sin (A + B) + sin 30°
4/3 = sin (A + B) + 1/2
4/3 - 1/2 = sin (A + B)
sin (A + B) = 8/6 - 3/6 = 5/6

Mapel : Matematika
Kelas : XI SMA
Bab : Trigonometri

Pembahasan :
(A - B) = 30°
Sin(A - B) = Sin 30°
Sin A Cos B - Cos A Sin B = 1/2
2/3 - Cos A Sin B = 1/2
Cos A Sin B = 2/3 - 1/2
Cos A Sin B = (4 - 3)/6
Cos A Sin B = 1/6

Maka...
Sin (A + B) = Sin A Cos B + Cos A Sin B
Sin (A + B) = 2/3 + 1/6
Sin (A + B) = 4/6 + 1/6
Sin (A + B) = 5/6