Question

求大神帮忙解决这两道大一微积分题，要步骤

Answer 1

(1)lim(e^x-e^(-x)-2x)/(x-sinx)
分子分母同时趋于0,用洛不答法则,同时求导数:
=lim(e^x+e^-x-2)/(1-cosx)
再次用洛不答法则:
=lim(e^x-e^-x)/sinx
再次:
=lim(e^x+e^(-x))/cosx
=(1+1)/1
=2
lim(x/(x-1)-1/lnx)
=lim (xlnx-x+1)/[(x-1)lnx)]
用洛不答法则:
=lim(lnx+1-1)/(lnx+(x-1)/x)
=lim lnx/(lnx+1-1/x)
再用一次:
=lim(1/x)/.(1/x+1+1/x^2)
=(1/1)/(1/1+1+1/1^2)
=1/3

追问

谢谢你啦😄

Answer 2

略看了一下，还是不会