lim x—>-2 (1/(x+2) - 12/(x^3 +8) ) 求极限~

lim x—>-2 1/(x+2)-12/(x^3 +8)=lim x—>-2 (x^2-2x+4)/(x^3 +8)-12/(x^3 +8)=lim x—>-2 [x^2-2x-8]/(x^3 +8)由于分子分母都趋向于0,所以可以用洛必达法则,上下求导.得上式=lim x—>-2 (2x-2)/3x^2=[2*(-2)-2]/3*(...