若lim(2^n /[2^(n+1) +a^n)]=0,则实数a取值范围是?

lim(n+3)(4-n)/(n-1)(3-2n) lim[(n+3)/(n+1))]^(n-2) 【n无穷大】 lim(2^n+3^n)^1 (n趋向无穷) lim(n^3+n)/(n^4-3n^2+1) lim(1-1/n)^(n^2)=? lim(1-1/n^2)^n=? 若lim(1+2+…+n)/n^2, lim In(n+1) / In(n+2) 是多少lim [In(n+1) / In(n+2)] 是多少 求1.lim(3n-(3n^2+2n)/(n-1)) 2.lim(8+1/(n+1)) 3.lim根号n(根号(n+1)-根号(n-3)) lim根号n^2+n+1/3n-2 lim根号n^2+n+1/3n-2=? lim (2n-1)/(2^n)=?n=>无穷大 lim n->无穷大(2^n-1)/(3^n+1) lim (1+1/2n)^n n趋向于无穷大 lim n->∞{2/((1+ 1/n )^n)}=? lim(1+1/(n+2))^n其中n趋近无穷 求极限n~∞,lim(n+1)/2n lim(根号(n平方+2n)-根号(n平方-1))