lim(x→无穷)x[ln(x-2)-ln(x+1)] 洛必达法则

2025-06-22 08:04:23
推荐回答(1个)
回答1:

im(x→∞) x[ln(x-2)-ln(x+1)]
=lim(x->∞) [ln(x-2)-ln(x+1)]/(1/x)
=lim(x→∞) [1/(x-2)-1/(x+1)]/(-1/x^2)
=lim(x->∞) -[(x+1-x+2)/[(x-2)(x+1)]x^2
=lim(x->∞) -3x^2/(x^2-x-2)
=-3