Brahmagupta's problem

{{Short description|Mathematics Problem}}

This problem was given in India by the mathematician Brahmagupta in 628 AD in his treatise Brahma Sputa Siddhanta:

Solve the Pell's equation

: $x^2\; -\; 92y^2\; =\; 1$

for integers $x,y>0$.

Brahmagupta gave the smallest solution as

: $(x,y)\; =\; (1151,120)$.