你好!lim[3/(1-x³) + 1/(x-1)]=lim [ - 3/(x³-1) + (x²+x+1)/(x-1)(x²+x+1) ]=lim (x²+x -2) / [(x-1)(x²+x+1)]=lim (x-1)(x+2) / [(x-1)(x²+x+1)]=lim (x+2)/(x²+x+1)= 1
解:这样做3/1-x^3+1/x-1=3-(x^2+x+1)/1-x^3=-x^2-x+2/1-x^3=-(x-1)(x+2)/(1-x)(x^2+x+1)=x+2/x^2+x+1把x=1代入得极限为1
原式=lim{3(x-1)/[1-(x-1)^2*(x^2+x+1)]} =lim{3(x-1)/[1-3(x-1)^2]} =0
请将表达式写清楚,括号,谢谢
等于1