Pell's Equation/Historical Note

Historical Note on Pell's Equation

It is popularly believed that Pell's Equation was misattributed to John Pell by Euler, and that it was in fact William Brouncker who was the first European to solve it.

However, Pell's Equation appears in Teutsche Algebra by Johann Heinrich Rahn ($1659$), which was certainly written with Pell's help, and possibly written entirely by Pell.

Some sources attribute Pell's Equation to Pierre de Fermat.

Pell's Equation had been extensively investigated by Brahmagupta and subsequent mathematicians of the Indian tradition as far back as $628$ C.E.

Subsequently Bhaskara II in the $12$th century and Narayana Pandit in the $14$th found solutions.

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $4,729,494$
• 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): Pell's equation
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $4,729,494$
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): Pell's equation
• 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): Pell's equation