This article describes a model icosidodecahedron made from cardboard and used as a lampshade. (MM)

This article demonstrates an iterative method of evaluating the cosine function which can be derived using secondary school trigonometry. A sample computer run is included. (MM)

To improve mathematics skills of freshmen, the College of Engineering at the University of Illinois at Urbana-Champaign has instituted a mathematics placement test and a summer algebra and trigonometry review program. (BB)

Suggests an alternative proof by analytic methods, which is more accessible than rigorous proof based on Euclid's Elements, in which students need only apply standard methods of trigonometry to the data without introducing new points or lines. (KHR)

Presents proofs of some trigonometric identities from a geometric point of view. (MKR)

Describes an analysis of the direction taken by a baseball immediately after coming into contact with the bat. Uses geometry, trigonometry, and physics. (MKR)

Prospective secondary teachers can explore mathematics at their own level by using the law of cosines to establish connections between topics that are usually taught separately such as cosine of the difference of two angles, Cauchy's inequality, determinants, sine of the difference of two angles, triangle inequality, and inner product of two…

Uses the average-monthly-temperature function as an application of the sine wave. Argues that the attractive aspect of gas bill graphs is that they clearly illustrate that sinusoidal curves are useful and meaningful in an everyday context. (ASK)

An integral, either definite or improper, cannot always be computed by elementary methods, such as reversed usage of differentiation formulae. Graphical properties, in particular symmetries, can be useful to compute the integral, via an auxiliary computation. We present graded examples, then prove a general result. (Contains 4 figures.)

This article outlines an engineering problem requiring the use of a specialized trigonometric formula, and offers an answer to that age-old classroom question, "When are we gonna have to use this"?

This paper was prepared in response to the Conference Board of Mathematical Sciences recommendations for the preparation of secondary teachers. It shows how using trigonometry as a conceptual tool in spreadsheet-based applications enables one to develop mathematical understanding in the context of constructing geometric representations of unit…

Theorems about the hyperbola which are ordinarily introduced in calculus courses can be proved without using the calculus. (SD)