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数学
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sin2α-cos2α+1/1+tanα怎样化简成2sinαcosα?
人气：114 ℃ 时间：2019-12-26 14:31:21
解答
=(2sinacosa+2sin^2a)/(1+sina/cosa)
=2sina*(sina+cosa)/[(sina+cosa)/cosa]
=2sina/(1/cosa)
=2sinacosa
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