x>0,h(x)=f(x)/x=mx-1+(2m-1)/xh'(x)=m-(2m-1)/x^2函數(shù)h(x)在區(qū)間[1,2]上是增函數(shù)即x∈[1,2],h'(x)=m-(2m-1)/x^2≥0恒成立即 mx^2≥2m-1當(dāng)m=0時,0≥-1,成立當(dāng) m>0時,mx^2∈[m,4m],需m≥2m-1 =>m≤1當(dāng)mm≥-1/2綜上所...