Definition:Pi/Historical Note/Notation

Historical Note on $\pi$ (Pi)

While the concept of $\pi$ (pi) dates back to antiquity, the standard symbol $\pi$ that is used for it dates back only to the $18$th century.

$\pi$ appears to have been first used for it for the first time by William Jones in $1706$, in his Synopsis Palmariorum Matheseos.

Jones followed earlier abbreviations for the Greek word periphery (περιφέρεια) by Oughtred and others.

Until fairly recently, it had been believed to date back only as far as Leonhard Paul Euler, who used it in his influential Introductio in Analysin Infinitorum of $1748$.

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972 \ldots$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41971 \ldots$