cos (4x-2y) cos (4x+2y)
Matematika
sekar195
Pertanyaan
cos (4x-2y) cos (4x+2y)
1 Jawaban
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1. Jawaban Anonyme
TriGonoMetRi
cos a + cos b = 2 cos (a+b)/2 cos (a-b)/2
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cos (4x - 2y) cos (4x + 2y)
= 1/2 (cos (4x - 2y + (4x + 2y)) + cos (4x - 2y - (4x + 2y))
= 1/2 (cos 8x + cos (-4y))
= 1/2 (cos 8x + cos 4y)