令t=x-1,则t→0lim【x→1】{[x^(3x-2)-x]·sin2(x-1)}/(x-1)³=lim【t→0】{[(t+1)^(3t+1)-(t+1)]·sin2t}/t³=lim【t→0】{[(t+1)^(3t+1)-(t+1)]·2t}/t³=2lim【t→0】[(1+t)^(3t+1)-1-t]/t² →...