prove that tan²theta/(1+sectheta)² = 1-costheta/1+costheta.
Matematika
kunal1
Pertanyaan
prove that tan²theta/(1+sectheta)² = 1-costheta/1+costheta.
1 Jawaban
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1. Jawaban Anonyme
jawab
theta =x
tan² x/ (1 + sec x)² =
= (sin² x / cos ²x) / ( 1+ 1/cos x)²
= (sin² x/ cos² x) / ( 1+ 2/cos x + 1/cos² x)
= (sin² x ) / (cos² x)(1 + 2/cos x + 1/cos²x)
= (sin² x) /(cos² x + 2 cos x + 1)
= (sin² x) /(cos x + 1)²
= (1 - cos² x)/ (1 +cos x)(1 + cos x)
= (1 + cos x)(1 - cos x) / (1 + cos x )(1 + cos x)
= (1- cos x)/(1 + cos x)