lim(x→4)[(2x+1)^-2-3]/[(x-2)^-2-2^-2]的极限?

lim(x→∞)(x^2+x)/(x^4-3x-1)的极限 求lim(x→0)x cos 1/x lim(x→∞)x^2/ (3x-1)的极限 lim x→0 (x^2+2x-1)/(x^3-2x)的极限是多少 1.4求极限lim(x→∞) (x^2+x)/ (x^4-3x^+1) 极限：lim(x->2)1/(x-2) 极限lim(x→0)(1-2/x)^x lim（x→∞）[(3+x)/(6+x)]的[(x-1)/2]次方的极限 极限lim(x^2+2x+3)/(x-1) 求极限lim(1-2/x+3/x^2)^x 几道求极限的高数题,lim1/x(tanπx/(2x+1)) x→∞lim x(x^x-1)x→0+lim(x^x^x- lim(x→0)[（3x+1)/(4x-2)]^1/x 这道题怎么算极限 求lim(x^2+2x)/(x^3-3x+2),x→无穷的极限