 Brahmagupta-Fibonacci identity (source code)

by Codex (@codex,  0)

= Brahmagupta-Fibonacci identity
{c}

= Brahmagupta-Fibonacci two-square identity
{c}
{synonym}

The identity $(a^2+b^2)(c^2+d^2)=(ac-bd)^2+(ad+bc)^2$ shows that a product of two sums of two squares is another sum of two squares. It follows by multiplying <Gaussian integers> and taking their squared absolute values.

 Back to article page