by John on (#6FCJC)
Yesterday I wrote a post that looked at the hyperbolic tangent sum for x and y strictly between -1 and 1. This sum arises when adding velocities in special relativity. The post ended with a description of the expression for in terms of elementary symmetric polynomials but did not offer a proof. This post will [...]The post Tanh and elementary symmetric polynomials first appeared on John D. Cook.