Hey. I have a question on Descartes Circle Theorem:
is a circle with radius r.
and are two equal circles that touch at a point T, and with a common tangent L. The circle touches both and externally and also shares the common tangent L. There exists a chain of circles for such that touches and externally. Find in terms of r.
I shall try and supply a picture.
Using inversion, I've worked out that . However, I would like to derive this using Descartes Circle Theorem. Any ideas?