8cos82,5drajat co37,5drajat tentukan nilainya
Matematika
rony60
Pertanyaan
8cos82,5drajat co37,5drajat tentukan nilainya
1 Jawaban
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1. Jawaban DB45
Trigon0metri
konsep
2 cos A cos B = cos A + cos B
.
8 cos 82,5 cos 37,5 = 4 [ 2 cos 82,5 cos 37,5 ]
= 4 [ cos (82,5 + 37,5) + cos (82,5 - 37,5)]
= 4 [ cos 120 + cos 45]
= 4 [cos (180-60) + cos 45]
= 4 [ - cos 60 + cos 45 ]
= 4 [- 1/2 + 1/2 √2 ]
= -2 + 2√2
atau
= 2√2 - 2