Jika tan 1/2A =p maka cos A adalah.. tolong dijawab ya
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Jika tan 1/2A =p maka cos A adalah.. tolong dijawab ya
1 Jawaban
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1. Jawaban whongaliem
tan (1/2 A) = p
tan² (1/2 A) + 1 = 1/cos² (1/2 A)
p² + 1 = 1 /cos² (1/2 A)
cos² (1/2 A) = 1/(p² + 1)
sin² (1/2 A) = 1 - 1/(p² + 1)
= (p² + 1 - 1) / (p² + 1)
= p² / (p² + 1)
cos A = cos² (1/2 A) - sin² (1/2 A)
= {1/(p² + 1)} - {p² / (p² + 1)}
= (1 - p²) / (p² + 1)