# question about DE of all circles in the plane. [closed]

There was a review question about DE of all circles in the plane.

I wish to re-visit and moderate my own remarks somewhat to serve politeness made after Phanindra's comment (that I hold correct) and the others but I cannot access it anymore.

There I obtained

$$y^{'''}= \frac{3 y^{'}y^{''2}}{(1 + y^{'2})}$$

but it had to be cramped into the question itself.This was about 30 minutes earlier.