请问你的题目能再清晰表达些吗?是根号xsinx 吗?
如果是的话,则解如下:
首先利用等价无穷小sinx ~ x
则在x趋于无穷大时,
lim ( ( 根号(xsinx) ) /(x+1))
= lim ( ( 根号(x^2) ) /(x+1))
= lim ( ( x ) /(x+1))
= lim ( 1/ ( 1+ (1/x) ) )
=1
lim(x趋于∞)(√xsinx)/(x+1)
=lim(x趋于∞)(sinx)/(√x+1/√x)
=0.
sqrt(x)/(x+1)=0,