若 lim 2n—根号(4n^2-kn+3) =1,则k=?
问题描述:
若 lim 2n—根号(4n^2-kn+3) =1,则k=?
答
2n—根号(4n^2-kn+3)=(kn-3)/(2n+根号(4n^2-kn+3))lim 2n—根号(4n^2-kn+3)=lim(kn-3)/(2n+根号(4n^2-kn+3))=lim(k-3/n)/(2+根号(4-k/n+3/n^2))=(k-0)/(2+根号(4-0+0))=k/4=1k=4