buktikan identitas trigonometri(sin x - cos x)(1 + sin x cos x) = sin^3 x -cos^3x
Matematika
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Pertanyaan
buktikan identitas trigonometri(sin x - cos x)(1 + sin x cos x) = sin^3 x -cos^3x
1 Jawaban
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1. Jawaban Robinn
→ Catatan ↓
x^3 - y^3 = (x - y)(x² + xy + y²)
→ Jawab :
= sin^3x - cos^3x
= (sinx - cosx)(sin²x + sinxcosx + cos²x)
= (sinx - cosx)((sin²x + cos²x) + sinxcosx)
= (sinx - cosx)(1 + sinxcosx)
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