Mathematics

Brahmagupta

c. 598 to c. 668 CE, Bhillamala (Rajasthan) and Ujjain, India

The Brahmasphutasiddhanta made zero a number and negatives legitimate, gave the area of a cyclic quadrilateral, and posed the Pell equation a thousand years before Europe.

Start learning Brahmagupta →

Lessons

Zero Becomes a Number

How Brahmagupta’s Brahmasphutasiddhanta (628 CE) turned zero from a mere placeholder into a number with its own arithmetic - the first known rules for calculating with nothing, including the honest, unfinished que…

Fortunes and Debts: Making Negatives Legitimate

Brahmagupta’s first systematic rules for signed arithmetic - positive quantities as ‘fortunes’ and negatives as ‘debts’ - which made numbers less than nothing into legitimate quantities, wi…

The Area of a Cyclic Quadrilateral

Brahmagupta’s celebrated formula for the area of a four-sided figure from its sides alone - the generalisation of Heron’s triangle formula - together with his deep results on cyclic quadrilaterals, and the s…

The Pell Equation, a Thousand Years Early

Brahmagupta’s attack on the ‘square-nature’ problem - finding whole-number solutions of Nx² + 1 = y² - through his ingenious method of composition , which builds infinitely many solutions fro…

The Round Earth, Gravity, and the Demon Rahu

Brahmagupta’s astronomy - a spherical earth that draws heavy things toward it, planetary and eclipse computation by geometry - set against his stubborn conservatism: he rejected Aryabhata’s rotating earth an…

More in Mathematics

EuclidPythagorasAl-KhwarizmiAlan TuringGottfried LeibnizAryabhataHypatia of AlexandriaBlaise Pascal
← All thinkers

epoché — a humanities education that remembers you.