This classroom note includes the following sections: Introduction; The General Case; and Related Formulas.

This article shows how to use six parameters describing the International Space Station's orbit to predict when and in what part of the sky observers can look for the station as it passes over their location. The method requires only a good background in trigonometry and some familiarity with elementary vector and matrix operations. An included…

In this 15-week study the effects of motivational email messages on learner self-efficacy and achievement in an asynchronous math course were investigated. A repeated measures design was used. One hundred, ninety-six participants were randomly assigned to control and experimental groups. Specially designed email messages were sent weekly to both…

Over the years the technology behind displaying the image of the unit circle has changed, but the defining features remain constant. The key question for the author as a teacher is this: are the relationships embodied in the image simple, memorable and rich enough to be grasped by any KS3 student at his school? It needs to be simple enough to…

This final article focuses in particular on the engagement of year 8 students who were taught trigonometry using dynamic geometry software ("Geometer's SketchPad"), as outlined in "MT214" and with resources from the ATM website. The project was implemented in three different classrooms in two different, multiracial,…

A 2 m long wooden beam provides an ideal demonstration tool for exploring moments. A class set is cheap and can be used at introductory and advanced levels. This article explores how such beams can be used to support learning about moments, equilibrium, vectors, and simultaneous equations. (Contains 7 figures.)

This textbook covers geometry and trigonometry and presents problems for student consideration. Geometry principles are applied to surface and solid measurement. Tables of logarithms and logarithmic sines are included. [This book was translated from the French of A. M. Legendre. It was revised and abridged by Charles Davies.]

This textbook covers geometry and trigonometry and presents problems for student consideration. Contents include geometry, plane trigonometry, analytical trigonometry, spherical trigonometry, and mensuration. [This book was adapted by Charles Davies.]

This textbook presents principles, ratios and proportions, the circle and measurement of angles, the proportions of figures and the measurement of areas, regular polygons and measurement of the circle, planes and solid angles, polyhedrons, the three round bodies, spherical triangles and spherical polygons, regular polyhedrons, plane and spherical…

The triangular array formed from the coefficients of sin + cos is discussed in relation to Pascal's triangle. (JG)

The typical precalculus book contains the obscure trigonometric identities known as the product-to-sum formulas. They usually get short treatment (or none) in a precalculus course because they are so rarely used. This is unfortunate since they have an interesting history. Before the invention of logarithms they were used to perform multiplications…

In the year 1837 mathematical proof was set forth authoritatively stating that it is impossible to trisect an arbitrary angle with a compass and an unmarked straightedge in the classical sense. The famous proof depends on an incompatible cubic equation having the cosine of an angle of 60 and the cube of the cosine of one-third of an angle of 60 as…

By selecting certain special triangles, students can learn about the laws of sines and cosines without wrestling with long decimal representations or irrational numbers. Since the law of cosines requires only one of the three angles of a triangle, there are many examples of triangles with integral sides and a cosine that can be represented exactly…

This book is primarily a scholarly monograph on ancient Chinese theory and application concerning the right triangle, based on evidence contained in classical mathematics texts and scrolls. It is also the first complete English translation of the ninth chapter of the Chiu chang suan chu, the richest source of problems from antiquity dealing with…

I present an operational model of how students simplify trigonometric expressions. The model has three main components: recognising, recalling and doing. This paper describes the interaction between these components and links this model to other models of doing mathematics. (Contains 2 figures and 1 table.)