A general rule for quadratic equations
AI-drafted · awaiting admin review
Babylonians solved particular quadratic problems about 1800 BCE. Brahmagupta (628 CE) wrote the earliest surviving general rule; Indian textbooks name a later version after Sridharacharya.
Indian contribution, later developed elsewhereMathematics & astronomy
Indian claim
The quadratic formula is Indian: Sridharacharya's formula.
Evidence for the Indian claim
- Brahmagupta's Brahmasphutasiddhanta (628 CE) states in words a general rule for solving a quadratic, the earliest surviving one.
- Sridhara's rule (often dated to the 9th–10th century; dates vary) is quoted by Bhaskara II, and Indian school books call it Sridharacharya's formula.
- Indian rules allowed negative quantities, so one rule covered many cases.
Commonly credited to
Babylonians solved quadratic problems much earlier, and al-Khwarizmi's algebra (9th century) is the source of 'algebra' in Europe.
Evidence for the other claim
- Old Babylonian tablets (c. 1800–1600 BCE) solve particular quadratic problems by steps equivalent to completing the square.
- Al-Khwarizmi (c. 820 CE) treated six types of equations separately with geometric proofs and did not use negative solutions.
- The symbolic formula as written today took shape in 16th–17th century Europe.
What historians and scientists say
Quadratic problems were solved first in Babylonia. The first known general rule is Brahmagupta's, and it is fair to credit India with that step.