tgα=2,则1/(1+sinα)+1/(1-sinα)=?

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tgα=2,则1/(1+sinα)+1/(1-sinα)=?

tgα=2,则1/(1+sinα)+1/(1-sinα)=?
tgα=2,则1/(1+sinα)+1/(1-sinα)=?

tgα=2,则1/(1+sinα)+1/(1-sinα)=?
化简式子=2/cosα^2 =2secα^2=2(tgα^2+1)=10

(1-sinα+1+sinα)/cosα^2=secα^2=1+tgα^2=5

tga=sina/cosa=2两边平方有
sin^2a/cos^2a=4
(1-cos^2a)/cos^2a=4
cos^2a=1/5
1/(1+sina)+1/(1-sina)(通分)
=(1-sina+1+sina)/(1-sin^2a)
=2/cos^2a=10