Notes
parallelogram identity

Parallelogram Identity

The parallelogram identity says that for vectors u→\vec{u} and v→\vec{v} then the length ‖⋅‖\|\cdot\| satisfies:

‖u→+v→‖+‖u→−v→‖=2‖u→‖+2‖v→‖ \|\vec{u} + \vec{v}\| + \|\vec{u} - \vec{v}\| = 2 \|\vec{u}\| + 2\|\vec{v}\|
Created on November 10, 2025 22:13:05 by Andrew Stacey?