求高数大神解定积分题？

Question

如题所述

Answer 1

原式=lim(x->0) [∫(0,x)(arctant)^2dt]/[(1/2)*x^2]
=lim(x->0) [(arctanx)^2]/x
=lim(x->0) (x^2)/x
=lim(x->0) x
=0本回答被网友采纳