Tunjukan bahwa : Cos 4x (1 + 2 cos x ) = cos 3x + cos 4x + cos 5x
Matematika
DaniellaVanessa3815
Pertanyaan
Tunjukan bahwa : Cos 4x (1 + 2 cos x ) = cos 3x + cos 4x + cos 5x
1 Jawaban
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1. Jawaban Anonyme
cos 4x ( 1+ 2 cos x ) = cos 3x + cos 4x + cos 5x
cos 4x + 2 cos 4x cos x = cos 3x + cos 4x + cos 5x
cos 4x + cos (4x+x) + cos (4x -x) = cos 3x + cos 4x + cos 5x
cos 4x + cos 5x + cos 3x = cos 3x + cos 4x + cos 5x
cos 3x + cos 4x + cos 5x = cos 3x + cos 4x + cos 5x