Cos 15 cos 105 - sin 15 sin 105 = ?
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Pertanyaan
Cos 15 cos 105 - sin 15 sin 105 = ?
2 Jawaban
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1. Jawaban Magriby
cos 15 cos 105 - sin 15 sin 105 = cos (15 +105)
= cos (120) = -1/2 -
2. Jawaban afhita27
cosacosb-sinasinb = cos (a+b)
Cos 15 cos 105 - sin 15 sin 105 = cos (15+105)
= cos 120
= cos (90+a)
= cos (90+30)
= -sin a
= -sin 30
= -1/2