Education Technology

Precalculus: Exploring the Parabola
by Texas Instruments

Published on April 03, 2013

Overview

Students explore the key features of the parabola, both geometrically and algebraically.

Key Steps

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    In problem 1, students will use a sheet of paper to explore parabolas. They will start by marking a point on the center of the paper and producing a series of folds along one of the longer edges that pass through this point.

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    Tracing along these straight-line folds should produce an envelope of lines, and the locus formed by the paper folding gives and approximation of a parabola. Students may use Cabri® Jr. to do a similar exploration.

    Students move on to fitting a parabola, they use the formula 4p(y - k) = (x - h)2 to assist them in their exploration.

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    At the end of this activity, students will be able to write and graph an equation of a parabola with vertex at (h, k) and axis of symmetry x = h or y = k. Students will also be able to derive the formula for any conic.