Teachers using these graphing tasks experienced engagement in understanding the need for the coordinate system.

### Bryan C. Dorner

Students who have grown up with computers and calculators may take these tools' capabilities for granted, but I find something magical about entering arbitrary values and computing transcendental functions such as the sine and cosine with the press of a button. Although the calculator operates mysteriously, students generally trust technology implicitly. However, beginning trigonometry students can compute the sine and cosine of any angle to any desired degree of precision using only simple geometry and a calculator with a square root key.

### Sarah D. Ledford, Mary L. Garner and Angela L. Teachey

Interesting solutions and ideas emerge when preservice and in-service teachers are asked a traditional algebra question in new ways.

### Jon D. Davis

Technology is in a constant state of flux. As a result, if we seek to use the latest forms of technology in our teaching, our teaching with technology must be ever changing. Edwards and Özgün-Koca (2009) describe an investigation involving the TI-Nspire CAS to understand the effect of b on the graphical representation of a quadratic function of the form *f (x) = ax ^{2} + bx + c*. Adapting this idea, I show how updates to technology can enhance this investigation to create an even more motivating and compelling experience for students. The investigation will make use of sliders and the spreadsheet capability of the TI-Nspire (the directions provided here apply to the TI-Nspire CX CAS).

### Joel A. Bryan

During the thirteen years that I taught high school physics and mathematics, I found that my physics students typically came to class excited to learn. As in all science classes, they interacted with fellow classmates while performing laboratory investigations and other group activities requiring higher-order thinking skills. To create a similar experience for my mathematics students, I developed a laboratory investigation for my precalculus class. These students responded just as favorably as my physics students to hands-on data collection activities.

### Marlena Herman

An introduction to definitions and equations of conic sections can be extended to explain the significance of the determinant.

### Helen M. Doerr, Donna J. Meehan and AnnMarie H. O'Neil

Building on prior knowledge of slope, this approach helps students develop the ability to approximate and interpret rates of change and lays a conceptual foundation for calculus.

### Gregory D. Foley

Ellipses vary in shape from circular to nearly parabolic. An ellipse's eccentricity indicates the location of its foci, but its aspect ratio is a direct measure of its shape.

### Peter T. Malcolm and Robert Q. Berry III

Technology from the Classroom is the venue for sharing articles that illustrate the effective use of technology in pre-K—grade 6 mathematics classrooms.

### Joyce M. Meredith

A short, easy lesson to introduce standard deviation involves calculator use and pencil and paper computation.