lim x(x+2)/x^2 (x→oo)lim 1/sin(x-2) (x→2)

lim x(x+2)/x^2 (x→oo)lim 1/sin(x-2) (x→2) lim 4n^2+2/3n^2+1 (n→oo)lim (√（n+1）- √（n）) (n→oo)lim √x+△x - √x / △x (△x→0)lim 1+2+…+n / n^2 (n→oo) Lim [x^2/(x^2-1)]^x (x→∞) lim(1+x/x)2x (x→∞) lim(x→0)e^x-x-1/x^2 lim x→1 x-1/x^2-x lim(x→0)[e^x-e^(2x)]/x lim xsin(2/x) x→∞ lim(1-x)^(2/x) x->0 lim(x(sin)^2) lim(x)lim(x→∞) [(x-1)/(x+1)]^2x 为什么 lim(x->∞) {[(-2)/(x+1)]*2x} = -4 lim x→∞ (x+sin 2x)/2 lim(x→0)(cosx-cos^2x)/x^2 lim(x→∞)(1-2/x)^2x x/2-1lim(1-2/x)x→∞ lim(x→0) (3x^2-5x+2), lim (x^3-x^2+4x)/(x^2+x) x→ 0 lim(x→1)(x^3-3x+2)/(x^3-x^2-x+1)