diketahui cos(A+B)=2/5 dan cosA×cosB=3/4 nilai tanA×tanB=
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diketahui cos(A+B)=2/5 dan cosA×cosB=3/4 nilai tanA×tanB=
1 Jawaban
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1. Jawaban dharmawan14
cos (A+B) = cos A cos B - sin A sin B
3/4 - sin A sin B = 2/5
sin A sin B = 3/4 - 2/5
sin A sin B = 15/20 - 8/20
sin A sin B = 7/20
tan A tan B = (sin A sin B)/(cos A cos B)
= (7/20)/(3/4)
= 28/60
= 7/15