# Mathematical Treasure: Lacroix on Differences and Series

Author(s):
Frank J. Swetz (The Pennsylvania State University)

Sylvestre Lacroix’s Traité des Différences et des Séries (1800) was the last volume of his magnum opus on calculus. It discussed the methods of finite differences in the numerical solutions of the definite integral.

The first page of the table of contents refers to the work having been accomplished by other mathematicians in the field of finite differences.

Lacroix proceeded to describe finite techniques and to introduce the $\Delta$ (delta) notation for difference.

The images above were supplied through the courtesy of ETH-Zürich via the e-rara website.

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Lacroix on Differences and Series," Convergence (July 2018)