mx^2+2(m-1)x+m-1=0判别式=4(m-1)^2-4m(m-1)=4(m-1)(m-1-m)=4(1-m)≥0m≤1两个根分别为tanα,tanβ根据韦达定理：tanα+tanβ = -2(m-1)/mtanα * tanβ = (m-1)/mtan(α+β) = (tanα+tanβ)/(1-tanα * tanβ )= {...