y=(x+1)arctan√x 求dy
问题描述：
y=(x+1)arctan√x 求dy
答
dy=arctan√xd(x+1)+(x+1)darctan√x
=arctan√xdx+(x+1)*1/(1+x)d√x
=arctan√xdx+1*(1/2√x)dx
=[arctan√x+1/(2√x)]dx