(x-x³)/(1+x)=x(1-x²)/(1+x)=x(1-x)=x-x²对於搜和仿任意E>0,|x-x²+2|=|x-2|*|x+1|∵|x-2|=|x+1-3|≤|x+1|+3∴限定0<棚此|x+1|<1,即-2则|x-2|≤|x+1|+3<4∴|x-x²+2|<4|x+1|∴取δ=min{1,E/4},则当0<|x+1|<δ时,有|x-x²+2|∴lim(x→-1)(x-x³)/(x+1)=-2
