You are here

Mathematical Treasure: De Morgan’s Trigonometry and Double Algebra

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

In 1849, Augustus De Morgan published his Trigonometry and Double Algebra, in which he considered some of the pedagogical issues of mathematics teaching at that time.

In his Preface, De Morgan defined the concept of “Double Algebra.”

Pages ix-xi of the “Table of Contents” provided an outline of the topics investigated under “Double Algebra.”

One of the major issues of mathematics teaching in this period was the concept of “negative numbers”: Just what are they? Mathematically speaking, how should they be handled?’ De Morgan addressed these questions in page 97.

On pages 101-103, De Morgan’s discussion of “Symbolic Algebra” began.

This material was obtained through the courtesy of the Peabody Library of Johns Hopkins University.

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: De Morgan’s Trigonometry and Double Algebra," Convergence (July 2016)