Diketahui cos A=7/26,sin B=5/13.AdanB sudut lancip, maka sin(A-B)=
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Pertanyaan
Diketahui cos A=7/26,sin B=5/13.AdanB sudut lancip, maka sin(A-B)=
1 Jawaban
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1. Jawaban rayysin
Sin(A-B)= sinA.cosB - cosA.sinB
Cos A=(samping/miring)=7/25
7=samping
25=miring
(pakai Δphytagoras);
24=depan
SinA=depan/miring=24/25
SinB=5/13
5=depan
13=miring
12=samping
CosB= samping/miring=12/13
Maka,
Sin(A-B)= sinA.cosB - cosA.sinB
=24/25.12/13 - 7/25.5/13
= 288/325 - 35/325
= 253/325