lim（x^2+2x-5）/（x^3+x+5）,x趋于无穷

lim（x^2+2x-5）/（x^3+x+5）,x趋于无穷 1.lim x->∞ （2x/x^2+1)*cosx 2..lim x->∞{ [(x^2-x)arctanx]/x^3-x-5}3..lim x->0 （e^x-e^-x-2x)/(x-sinx) 4..lim x->0 (sinx-x)/(x^3) 5..lim x->0 (x^2*tanx)/(x-tanx) 6..lim x->0 (1+3/x)^2x 7..lim x->0 (1+2x)^(3/sinx) 8.lim x->∞ (x/1+x)^(x-3) 9..li 用罗必达法则解 （见图）lim [(e^x)-1/sin（5x)]x->0lim [1-cos(5x)/1-cos(7x)]x->0lim x->0 [(8^x-7^x-1)/(x^2)-1]lim [1-(6/x)]^x x->∞ lim 7cos(3x)sec(9x)x->pi/2 lim(x→0) (3x^2-5x+2), lim(2x-3/2x+1）^x+1 数学难题,求指教~~极限到底是什么玩意我还不懂.1.lim（x^2-2x+6）2.lim(x^2-4)/(x-2）3.lim(x^2-6x=8)/(x^-5x=4)4.lim[1/(1-x)-1/(1-x^3)5.lim(sin2x)/x^26.lim(sin5x)/x7.lim(tan3x)/(sin7x)8.lim[(1+x)/x]^2x例如这道例题~lim[(1/3)x+1] 1、lim(x->无穷大) e^x arctanx2、lim(x->0)sinx√1+sin(1/x)3、lim(x->无穷大)【（√x^2+x+1）-【(√x^2-x+1)】4、lim(x->无穷大)((x+{x+(x)^0.5]^0.5}^0.5)/(2x+1)^0.55、lim(x->0)(sin3x+x^2sin1/x)/((1+cosx)x)6、lim(n->无穷大)(2^n)(si lim（3x^2*sin2/x）/（5x+3）,x—>0 求极限 lim（x->3）(x+1)/(x^2-5x+6) lim(x->无穷大){(2^x-3^x)/2}^(1/x) lim(x->0)((2-x)/(3-x))^1/x ( x+3) lim (------------)的x次方 x->∞ ( x-2) lim(1-(5/x))^x-2 已知lim(x→0）[f(3x)/x]=3 求lim(x→0) [2x/f(5x)] lim 2x³+3x²+5/7x³+4x²-1 的极限 ,lim e x5-1/x(e,x的五次方） lim（x趋于-2）x^2-x-6/x^2+3x+2 lim(x→∞)[(X^2+2x+5)/(3x^2-x+1) = lim(x->+∞）[3^x+2^x]/[(3^x+1)+(2^x+1)]