membuktikan (cos x + sin x)(cos x - sin x) =1-2 sin²x
Matematika
Adityo111
Pertanyaan
membuktikan (cos x + sin x)(cos x - sin x) =1-2 sin²x
1 Jawaban
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1. Jawaban Ro1899
=> cos^2 x - cos x sin x + sin x cos x - sin^2 x
= cos^2 x - sin^2 x
= 1 - sin^2 x - sin^2 x
= 1 - 2sin^2x