lim(n→∞)(1/(n^2+1)+4/(n^2+1)+7/(n^2+1)+3n-2/(n^2+1)=
问题描述：
lim(n→∞)(1/(n^2+1)+4/(n^2+1)+7/(n^2+1)+3n-2/(n^2+1)=
答
原式=lim(n→∞)[1+4+7+……+(3n-2)]/n²+1)
=lim(n→∞)[(3n-1)n/2]/n²+1)
=lim(n→∞)(3n²-n)/(2n²+2)
上下除以n²
=lim(n→∞)(3-1/n)/(2+2/n²)
=3/2