运用tanα/2=sinα/1+cosα=1-cosα/sinα化简1+sin2α-cos2α/1+sin2α+cos2α

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运用tanα/2=sinα/1+cosα=1-cosα/sinα化简1+sin2α-cos2α/1+sin2α+cos2α
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运用tanα/2=sinα/1+cosα=1-cosα/sinα化简1+sin2α-cos2α/1+sin2α+cos2α
运用tanα/2=sinα/1+cosα=1-cosα/sinα化简1+sin2α-cos2α/1+sin2α+cos2α

运用tanα/2=sinα/1+cosα=1-cosα/sinα化简1+sin2α-cos2α/1+sin2α+cos2α
(1+sin2α-cos2α)/(1+sin2α+cos2α)
=(1+sin2α-cos2α)/(1+sin2α+cos2α)
=[(sinα)^2+(cosα)^2+2sinαcosα-(cosα)^2+(sinα)^2]/(1+sin2α+cos2α)
=2sinα(sinα+cosα)/(1+sin2α+cos2α)
=2sinα(sinα+cosα)/(1+sin2α+cos2α)
=2sinα(sinα+cosα)/[(sinα)^2+(cosα)^2+2sinαcosα+(cosα)^2-(sinα)^2]
=2sinα(sinα+cosα)/[2cosα(sinα+cosα)]
=tanα