Find the Tangent Planes to Three Given Spheres

00:00 Introduction
00:34 Two key ideas
01:09 Reducing the problem from "three spheres" to "two spheres and a point"
01:52 Our strategy
02:05 Formulate the "reduced" problem in GA terms
03:31 Essential: Obtain expression for the outer product of the projections
04:15 A difficulty
04:36 Looking for an idea: The geometric representation of bivector addition
05:15 A surprising simplification!
06:40 A change in our strategy
07:15 The answer, and its geometric interpretation
09:15 An extension to a more-general case
09:25 Please consider joining the group "Pre-University Geometric Algebra"

Link for the document:
https://vixra.org/abs/2210.0104

LinkedIn group "Pre-University Geometric Algebra"
https://www.linkedin.com/groups/8278281/