Jika α + β = π/6 dan cos α cos β = 3/4 maka cos (α-β) = ... A. 1/9 - √3/2 B. 3/2 + √3/2 C. 3/4 - √3/2 D. 3/2 - √3/2 E. √3/2
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Pertanyaan
Jika α + β = π/6 dan cos α cos β = 3/4 maka cos (α-β) = ...
A. 1/9 - √3/2
B. 3/2 + √3/2
C. 3/4 - √3/2
D. 3/2 - √3/2
E. √3/2
A. 1/9 - √3/2
B. 3/2 + √3/2
C. 3/4 - √3/2
D. 3/2 - √3/2
E. √3/2
1 Jawaban
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1. Jawaban ryantian17
cos (A+B)= cos A cos B - Sin A sin B
cos (π/6)= ¾ -sin A sin B
½√3 = ¾ - sin A sin B
sin A sin B= ¾ - ½√3
Cos (A-B) = cos A cos B + Sin A sin B
= ¾+ ¾ - ½√3
= 3/2 -√3/2
jadi jawaban nya D