设n属于Z化简cos（4n+3）派/4+sin（3-4n）派/4

一道化简题化简：{1-cos[(

{1-cos[(7π/2)-2α]+cos(2α-7π)}/{1+sin[2α+6π]+sin[(3π/2)+2α]} ={1-cos[3π+(π/2)-2α]+cos(7π-2α)}/(1+sin2α-cos2α) ={1-cos[(π/2)-2α]+cos(6π+π-2α)}/(1+sin2α-cos2α) ={1-sin2α+cos(π-2α)}/(1+sin2α-cos2α) ={1-sin2α-cos2α}/(1+sin2α-cos2α) =[(sinα)^2+(cosα)^2-2sinαcosα-(cosα)^2+(sinα)^2]/ [(sinα)^2+(cosα) ^2+...全部

   {1-cos[(7π/2)-2α]+cos(2α-7π)}/{1+sin[2α+6π]+sin[(3π/2)+2α]} ={1-cos[3π+(π/2)-2α]+cos(7π-2α)}/(1+sin2α-cos2α) ={1-cos[(π/2)-2α]+cos(6π+π-2α)}/(1+sin2α-cos2α) ={1-sin2α+cos(π-2α)}/(1+sin2α-cos2α) ={1-sin2α-cos2α}/(1+sin2α-cos2α) =[(sinα)^2+(cosα)^2-2sinαcosα-(cosα)^2+(sinα)^2]/ [(sinα)^2+(cosα) ^2+2sinαcosα-(cosα)^2+(sinα)^2] =[2(sinα)^2-2sinαcosα]/[2(sinα)^2+2sinαcosα] =[2sinα(sinα-cosα)]/ [2sinα(sinα+cosα)] =(sinα-cosα)/(sinα+cosα) =(sinα/cosα-cosα/cosα)/(sinα/cosα+cosα/cosα) =(tanα-1)/(tanα+1) =[tanα-tan(π/4)]/[1+tanαtan(π/4)] =tan(α-π/4)。
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