求极限 x趋近于1+,lim[x/(x-1)-1/lnx]
问题描述:
求极限 x趋近于1+,lim[x/(x-1)-1/lnx]
答
先通分lim(x--->1+)[x/(x-1)-1/lnx]=lim(x--->1+)[(xlnx-(x-1))/(x-1)lnx]上下各求导=lim(x--->1+)[(1+lnx-1)/(lnx+(x-1)/x)]=lim(x--->1+)[lnx/(lnx+1-1/x)=lim(x--->1+)[xlnx/(xlnx+x-1)]再次上下求导=lim(x...