tana=-1/2,tan(a-b)=-2/5,则tanb=?

tan(a+b)-1/tana=2*tana 请化简! 已知tan(a-r)/tana+sin^2b/sin^2a=1 ,求证tan^2b=tana*tanr.. 已知tan(A-B)/tanA+sin^2C/sin^2A=1,求证：tanA×tanB＝tan^C求证tanA×tanB＝tan^2C tan(2a+b)=3,tan(a+b)=1,tana= tan(a+b)=2/5,tan(a-b)=1/4,求tana,tanb,tan2a 求证tan(A/2)-{1/(tanA/2)}=-2/tanA 求证tan(a/2)-1/(tana/2)=-2/tana 已知tan(A-B)/tanA+sin^2C/sin^2A=1,求证：tanA*tanB=tan^2C 已知tan(2A-B)=√3(1+M),tan(A-B)-√3[M-tan(2A-B)tan(A-B)],求tanA的值 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 tan(A+B)=tanA+tanB+tanAtanB? 已知A、B是锐角,求证(tan(π+A)+tan(-B))/(1/tan(3π-A)+tan(π/2-B))=tanA*tanB 已知A、B是锐角,求证(tan(π+A)+tan(-B))/(1/tan(3π-A)+tan(π/2-B))=tanA*tanB 已知锐角A.B满足tan(A+B)=2tanA,则tanA的最大值为? 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=? 已知tanA-(1/tanA)=2,其中A为锐角,求tan^2+(1/tan^2)