∵ lim(x->∞）（x^2+1)/(x+1) -ax-b = 0∴ 0=lim(x->∞）[（x^2+1)/(x+1) -ax-b ] / x =lim(x->∞）[（x+1/x)/(x+1) -a-b/x=lim(x->∞）[（1+1/x^2)/(1+1/x) -a-b/x= 1 - a - 0 = 1-a∴ a = 1∴ lim(x->∞）（x^2+1...