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已知(1+tan2α)/(1-tanα)=2010,求1/cos?

2012-02-03 17:23:55圆***
已知(1+tan2α)/(1-tanα)=2010,求1/cos2α+tan2α的值.已知(1+tan2α)/(1-tanα)=2010,求1/cos2α+tan2α的值.:为方便表达,设tanα=t,则 1/cos2α+tan2α =(1+?

最佳回答

  • 为方便表达,设tanα=t,则 1/cos2α+tan2α =(1+t^2)/(1-t^2)+2t/(1-t^2) =(1+t)^2/(1-t^2) =(1+t)/(1-t) =2010。
    2012-02-03 22:26:47
  • 题目应该写错了 1/cos2α+tan2α =1/[(cosα)^2-(sinα)^2]+2tanα/[1-(tanα)^2] =[1+(tanα)^2]/[1-(tanα)^2]+2tanα/[1-(tanα)^2] =(1+tanα)/(1-tanα) =2010
    2012-02-03 18:16:51
  • 很赞哦! (151)