若2tana=(1-tan^2a),则tan2a=

若锐角A满足tanA+1/(tanA)=3,则tan^2A+1/(tan^2A)=? tana+1/tana=9/4,则tan^2+1/sinacosa+1/tan^2a=? tana+1/tana=9/4,则tan^2+1/sinacosa+1/tan^2a=? 求证tan(A/2)-{1/(tanA/2)}=-2/tanA 求证tan(a/2)-1/(tana/2)=-2/tana tan(a+b)-1/tana=2*tana 请化简! 证明2tana/1-tan^2a证明2tana/1-tan^2a=tan2a tana+1/tana=3,求sina*cosa tan^2 a+1/tan^2 a 已知1-tanA/1+tanA=2+根号3,则tan(π/4+A)是 已知tanA-(1/tanA)=2,其中A为锐角,求tan^2+(1/tan^2) tan²a-2tana-3=0.tana=3或tana=-1 化简:tana+tan(派/2+a)+4tana/1-tanatana 若2tana=(1-tan^2a),则tan2a= 若tana=/13,tanb=1/2,则tan(2a+b)的值是 若(tana+1)(tanβ+1)=2,则a+β=? 若tana=1/2,则tan（a+pai/4)= tan(a/2)=?用tana表示 已知tan(A-B)/tanA+sin^2C/sin^2A=1,求证：tanA×tanB＝tan^C求证tanA×tanB＝tan^2C