cos 8x + cos 12x =.....?
Matematika
Putu1111111
Pertanyaan
cos 8x + cos 12x =.....?
1 Jawaban
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1. Jawaban Anonyme
TRIgonomeTRI
cos 8x + cos 12x
= 2 cos (8x + 12x)/2 cos (12x - 8x)/2
= 2 cos 10x cos 2x
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cos a + cos b = 2 cos (a + b)/2 cos (a - b)/2