为啥后面极限是1啊，我算起来是0

x^2.arcsin(x^2) -∫(0->x^2) u/√(1-u^2) du +x ~ x
ln(1+x) -1 ~x
(1/2)lim(x->0) [x^2.arcsin(x^2) -∫(0->x^2) u/√(1-u^2) du + x ]/[ln(1+x) -1]
=(1/2)lim(x->0) [x^2.arcsin(x^2) -∫(0->x^2) u/√(1-u^2) du +x]/x
=(1/2)lim(x->0) x/x
=1/2