答：属于0-0型,可以应用洛必达法则对分子分母分别求导再求极限(x→0) lim[(5x-sinx)/x^3] =(x→0) lim[(5-cosx)/(3x^2)]=(x→0) lim[(5-1)/(3x^2)]=+∞(x→0) lim[(5x-sinx)/x]^3 =(x→0) lim[(5-cosx)/1]^3=(x→0) ...
