by

Eun Jung

Construct a parabolar given a fixed points for the focus and a lne(segment) for the direx

a) Use an Action Button to generat the parabola from an animation and trace of a constructed point.

The line j is fixed line and the point A is the fixed point. When B is moving on the line j, C is in the same distance from the points A and B since C is on the line which is perpendicular to segment AB and through midpoint of segment AB. Thus trace of C become a parabola.

b) Repeat 8a wth a trace of the tangent line at the constructed point.

The line which perpendicular to segment AB is tangent line of parabola at point C.

c) Use the locus command to generated to the parabola from a constricted point or the tangent line at that point

The locus of C is parabola.

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