怎么证tan(45+a)=(1+tana)/(1-tana).
怎么证tan(90+a)=-1/tana
求证tan(a+π/4)=(1+tana)/(1-tana)
tan(a+b)-1/tana=2*tana 请化简!
求证tan(A/2)-{1/(tanA/2)}=-2/tanA
求证tan(a/2)-1/(tana/2)=-2/tana
怎么证明tanA x tan(90-A)=1
tan(A+90°)=-1/tanA
tan(90+a)=-1/tana
tan(A+B) = (tanA+tanB) / (1-tanA * tanB) = -1从而得到:tanA+tanB
tan²a-2tana-3=0.tana=3或tana=-1
若1-tanA/1+tanA=2+√3,则tan(45°+A)等于
tana+1/tana=3,求sina*cosa tan^2 a+1/tan^2 a