∵当x+∞]x^(2n)=0 lim[n-->+∞][1-x^(2n)]/[(1+x^(2n)]=1当x=1时lim[n-->+∞]x^(2n)=1 lim[n-->+∞][1-x^(2n)]/[(1+x^(2n)]=0当x>1时lim[n-->+∞]x^(-2n)=0 lim[n-->+∞][1-x^(2n)]/[(1+x^(2n)]=...