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Suggests that the cross product of two vectors can be more easily and accurately explained by starting from the perspective of dyadics because then the concept of vector multiplication has a simple geometrical picture that encompasses both the dot and cross products in any number of dimensions in terms of orthogonal unit vector components. (AIM)

Presents the hierarchical structure of quadrilaterals as an illustration of learning a geometric concept by moving from the levels of visualization and analysis to the level of formal deduction. The development discusses the classification of quadrilaterals, the inheritance of properties within the hierarchy, connections between algebra and geometry, and the concepts of definition and proof. (MDH)

Explores the role that symbolic-graphical calculators can play in the current calls for reform in the mathematics curriculum. Discusses symbolic calculators and graphing calculators in relation to problem solving, computational skills, and mathematics instruction. (MDH)

Presents a short study of proper values of two-by-two matrices with real entries. Gives examples of symmetric matrices and applications to systems of linear equations of perpendicular lines intersecting at the origin and central conics rotated about the origin to eliminate the xy term from its equation. (MDH)

Describes one teacher's reflection concerning the quest to develop an understanding of school mathematics that promotes and sustains students' opportunities for exploration and conjecture. Recounts that a particular student's exploration of the features of parabolas eventually led to an understanding of the quadratic formula precisely because of the endeavor to discover relationships between symbolic and graphical representations. (JJK)

Presents a model of the tutoring process that takes into account the evolving tutor/student relationship and the subject matter concerns that the tutor is helping the student master. Reports illustrative data from case studies from which the model is derived. (15 references) (MDH)

Presents a qualitative and global method of graphing functions that involves transformations of the graph of a known function in the cartesian coordinate system referred to as graphic operators. Explains how the method has been taught to students and some comments about the results obtained. (MDH)

Presents the results of a preliminary investigation into the feasibility of teachers constructing their own animations for the mathematics classroom using computer animation tools. Provides examples of animation constructed using "Ani ST" and "Mathematica" programs. Concludes that computer animation has potential to be a practical instructional tool. (MDH)

Several examples of solid figures that calculus students can use to exercise their skills at estimating volume are presented. Although these figures are bounded by surfaces that are portions of regular cylinders, it is interesting to note that their volumes can be expressed as rational numbers. (JJK)

Presented are student activities that involve two standard problems from geometry and calculus--the volume of a box and the bank shot on a pool table. Problem solving is emphasized as a method of inquiry and application with descriptions of the results using graphical, numerical, and physical models. (JJK)

Presented are activities concerning the method of graphing the equation y=kx in the Cartesian and other coordinate systems. Students progress from the graph of a straight line to the investigation of conceptually related geometric loci in non-Cartesian coordinate systems. (MDH)

In polar coordinates, the intersection of the graphs of two functions, f(x) and g(x), does not always correspond to the solutions of the equation f(x) = g(x). Presented are examples to illustrate this concept, proofs demonstrating why this is true, and a computer program to simultaneously plot polar coordinate graphs. (MDH)

Presented is a method of reorganizing a high school geometry course to integrate coordinate geometry together with Euclidean geometry at an earlier stage in the course, thus enabling students to prove subsequent theorems from either perspective. Several examples contrasting different proofs from both perspectives are provided. (MDH)

Discussed are properties possessed by polygons inscribed in the lattice parabola y=x, including the area of a triangle, triangles of minimum area, conditions for right triangles, triangles whose area is the cube of an integer, and implications of Pick's Theorem. Further directions to pursue are suggested. (MDH)

Presented are six short articles on an application of an ellipse to carpentry, the area of an ellipse by stacking, using the isoperimetric quotient to solve a minimum problem, using an ill-posed trigonometry problem to encourage deeper exploration of concepts, the volume and centroid of the Step Pyramid of Zoser, and a unique telescoping series with sum one. (MDH)

The third in a series of 3 articles, a study of 30 students was conducted to test the effect of restructuring a unit on trigonometric identities around microcomputer activities based on the themes of educational undercurrents identified in Part II. Experimental-group students scored significantly higher relating trigonometric functions to their graphical representations. (MDH)

The first in a series of three articles, successful instructional materials from a 15-year software development effort are analyzed and characterized with special attention given to educational experiences intended to shape students' perceptions of the fundamental nature, interconnectedness, and usefulness of mathematics. The software programs "Sort Equivalent Fractions,""Darts," and "Green Globs" are reviewed. (MDH)

Introduces the concept of maximum and minimum function values as turning points on the function's graphic representation and presents a method for finding these values without using calculus. The process of utilizing transformations to find the turning point of a quadratic function is extended to find the turning points of cubic functions. (MDH)

The geometry problems of finding rectangles that have numerically equal areas and perimeters knowing when the plane can be tessellated by congruent regular polygons are connected by the equation: m = 2n/(n-2). Three graphic approaches to the solution of the problem when m and n are integers are discussed. (MDH)

Describes an Apple computer program (listing available from author) which simulates Fraunhofer and Fresnel diffraction using vector addition techniques (vector chaining) and allows user to experiment with different shaped multiple apertures. Graphics output include vector resultants, phase difference, diffraction patterns, and the Cornu spiral (geometric representation of Fresnel integral). (JM)

Offers practical tips on teaching secondary mathematics topics. The ideas are classroom-tested approaches that offer new slants on familiar subjects. The topics discussed include the interpretation of mathematical symbolism in concrete terms, ellipses, and vectors. (PK)

Includes materials in reproducible format designed to help students read and draw distance-time graphs and use the slopes of these graphs to draw conclusions about car speed. (PK)

A handbook for teachers of calculus and analytic geometry is described. Five categories of materials are included, with illustrative examples and a lesson plan. (MNS)

Presents an easy-to-use Applesoft BASIC program that graphs rational functions and any asymptotes that the functions might have. Discusses the nature of rational functions, graphing them manually, employing a computer to graph rational functions, and describes how the program works. (TW)

Presents a method of viewing the reflective properties of the parabola and ellipse. Reinforces previously studied concepts of mathematics useful for individual or classroom projects. (PK)

Considers the problem of how to go from three coordinates to two. States that it is not a problem that mathematics students ordinarily encounter. Presents four methods of graphing three-dimensional figures on a two-dimensional computer screen. (PK)