lim ( x^3+4x+1)/(x^4+5x+4) x→无限

求极限 lim(x→∞)5x/(x-4) 求极限 lim(x→-∞)[(√1-x)-3] 1.4求极限lim(x→∞) (x^2+x)/ (x^4-3x^+1) lim(x→∞)(x^2+x)/(x^4-3x-1)的极限 lim(x->2) {(3x+16)^1/2-4}/x lim(x→∞)[(X^2+2x+5)/(4x^2-x+1) =(1+2/x+5/x^2)/(4-1/x+1/x^2)= 求极限：1.lim(x→∞) (3x^2 -2)/(x^4 +x^2 -1) 2.lim(x→∞) (4x^4 -2x^ 求极限值,limx→（x^2-1/x-1）和lim x→∞（2x^3-3x^2+4/5x^3+x-7)谢谢! 求极限：lim(x→1）根号5x-4-根号x/x-1 lim(x→0)[（3x+1)/(4x-2)]^1/x 这道题怎么算极限 lim(√(4x²-8x+5)+2x+1),x→-∞怎么解? 求极限lim(x→2)(x^2-3x+2)/(x^2+4x-12) 求极限lim (3x^3+5x^2+x) / (7x^3+5x-4)