分离得到：
dy/y=2xdx
两边积分：
ln|y|=x^2+C1
y=±e^c1 *e^x^2
=Ce^x^2 (C =±e^c1)
图片如下，看看能否看清楚？
dy/dx=2xydy/y = 2x dxTaking integrate to the both sidelny = x^2 y = e ^(x^2) + C where C is a constant
