Where does pi come from? Why should we be interested in negative numbers, or square roots of negative numbers? How did people ever figure out the quadratic formula? A truly wonderful reference for teachers at all levels.

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Problems from a 15th century French manuscript, including one with negative solutions

This is page 167 from the Exercitationes mathematicae (1657) of Frans van Schooten (1615-1660). This book contained a collection of mathematical construction problems, among much else. It was one of the books read by Isaac Newton while he was a student at Cambridge University and helped to introduce him to modern mathematics. On this page we see a construction enabling one to find the distance across a river.

A square walled city measures 10 li on each side. At the center of each side is a gate. Two persons start walking from the center of the city.

Prove geometrically that the hypocycloid is a straight line when the radius of the rolling circle is one-half the radius of the fixed circle.

Given a right triangle where you know the length of the base and the sum of the perpendicular side and the hypotenuse.

Given the frustum of a circular cone with height h.

The authors makes the case for Leonardo da Vinci as the first modern scientist, as he discussed Leonardo's mathematics and science.

A survey of concepts of infinite sets over the centuries.

A powerful, unvanquished, excellent black snake, 80 angulas in length, enters into a hole at the rate of 7 1/2 angulas in 5/14 of a day, and in the course of a day its tail grows 11/4 of an angula.