SERRET, Traité de trigonométrie, 1888

Joseph-Alfred Serret (1819-1885) was a distinguished French mathematician, member of the Institute and Bureau of Longitudes, and professor at the Collège de France and the Faculty of Sciences in Paris. His Treatise on Trigonometry is a classic textbook of the late 19th century, widely used in higher education. The work is recognized for its clarity and rigor in explaining the principles of trigonometry, fundamental to astronomy, navigation, and other branches of applied science.