极限题lim(1+1/2+1/4+.+1/2^n) n→无穷lim((x^2 -1)/(x^2 +3))^(x^2 +1

求极限：lim(x→无穷)(2^n-7^n)/(2^n+7^n-1)=? 极限题lim(1+1/2+1/4+.+1/2^n) n→无穷lim((x^2 -1)/(x^2 +3))^(x^2 +1 求极限,lim(x->0) (1-2sinx)^(3/x)lim(n->+∞) (n!-4^n) / (6+ln(n)+ 求极限lim(x→∞)（1/n+2/n+3/n..+n/n） lim(2^n+3^n)/[2^(n+1)+3^(n+1)] x->无穷 极限是多少 .3q 求极限lim(-2)^n+3^n/(-2)^[n+1]+3^[n+1] (x→∞) 求极限lim(x→无穷)1/n{(1+cosπ/n)^(1/2)+.+(1+cosn*π/n)^(1/2)} .. lim（x→无穷）（（1+n次根号下3）/2）^n求其极限 求极限lim [x^(n+1)-(n+1)x+n]/(x-1)^2 x趋于1 求极限 lim(n->无穷)[(3n^2-2)/(3n^2+4)]^[n(n+1)] 求极限 lim x-无穷 sin(n+1)/(n+a) 求极限 lim(n→∞)[(1+x)/(1+x^2n)] |x|＞1