Cos 130° cos 40° + sin 130° sin 40°
Matematika
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Pertanyaan
Cos 130° cos 40° + sin 130° sin 40°
1 Jawaban
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1. Jawaban Anonyme
jawab
cos A cos B + sin A sin B = cos (A - B)
cos 130 cos 40 + sin 130 sin 40 = cos (130 - 40)= cos 90 = 0