用复合函数求导,首先把arctan√x看成一个整体
dy=In（arctan√x）*2^arctan√x *d（arctan√x ）再把√x看成一个整体
=In（arctan√x）*2^arctan√x *1/（1+x）*d √x
=In（arctan√x）*2^arctan√x *1/（1+x）* 1/2√x dx