lim(x趋近去无限大)√(x的平方-3x)/2x+1
问题描述:
lim(x趋近去无限大)√(x的平方-3x)/2x+1
怎么做?急求
答
lim(x→∞)√(x²-3x)/2x+1
=lim(x→∞)√(x²-3x)/2x+1
=lim(x→∞)√ [ (x²-3x) /(4x²+4x+1)]
=lim(x→∞)√[ (1-3/x)/(4+4/x+1/x²) ](x→∞,1/x,1/x²→0)
=√1/4
=1/2