yet another proof of parallelogram law

Define g(ϵ)=x+ϵy,x+ϵy, where ϵ is real. Then g(ϵ)=x,x+ϵ(y,x+x,y)+ϵ2y,y. Hence,

Title yet another proof of parallelogram lawPlanetmathPlanetmath
Canonical name YetAnotherProofOfParallelogramLaw
Date of creation 2013-03-22 16:08:23
Last modified on 2013-03-22 16:08:23
Owner Mathprof (13753)
Last modified by Mathprof (13753)
Numerical id 5
Author Mathprof (13753)
Entry type Proof
Classification msc 46C05