cos 45° (1+2 cos 15°)
Matematika
france8
Pertanyaan
cos 45° (1+2 cos 15°)
1 Jawaban
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1. Jawaban whongaliem
cos 45° (1 + 2.cos 15°) = cos 45° + 2 .cos 45° . cos 15°
= cos 45° + cos (45° + 15°) + cos (45° - 15°)
= cos 45° + cos 60° + cos 30°
= 1/2 √2 + 1/2 + 1/2 √3
= 1/2 + 1/2 √2 + 1/2 √3
= 1/2 (1 + √2 + √3)