f=（ax+1）/（x+2a）(x≠-2a) = [a(x+2a)+1-2a²]/(x+2a) =a+(1-2a²)/(x+2a)f(x)在区间(-2,正无穷)上是增函数,(1) -2a≤-2 ,a≥1(2) 1-2a²<0 ,a²>1/2, ==>a<-√2/2或a>√2/2∴a的取值范围是a≥1希望能解决您的问题。
