Difference between revisions of "LocusEquation Command"
From GeoGebra Manual
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* If the locus is too complicated then it will return 'undefined'. | * If the locus is too complicated then it will return 'undefined'. | ||
* The calculation is done using [[w:Gröbner_basis|Gröbner bases]], so sometimes extra branches of the curve will appear that were not in the original locus.}} | * The calculation is done using [[w:Gröbner_basis|Gröbner bases]], so sometimes extra branches of the curve will appear that were not in the original locus.}} | ||
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{{betamanual|version=5.0|1= | {{betamanual|version=5.0|1= | ||
{{Note|1= | {{Note|1= | ||
In GeoGebra 5 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option <code><nowiki>--singularWS=enable:false</nowiki></code>).}}}} | In GeoGebra 5 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option <code><nowiki>--singularWS=enable:false</nowiki></code>).}}}} |
Revision as of 11:43, 23 November 2012
This page is about a feature that is supported only in GeoGebra 4.2. |
- LocusEquation[ <Locus> ]
- Calculates the equation of a Locus and plots this as an Implicit Curve.
- LocusEquation[ <Point Creating Locus Line Q>, <Point P> ]
- Calculates the equation of a Locus by using inputs tracer point Q and mover point P, and plots this as an Implicit Curve.
Example:
Let us construct a parabola as a locus: Create free Points A and B, and Line d lying through them (this will be the directrix of the parabola). Create free point F for the focus. Now create P on Line d (the mover point), then create line p as a perpendicular line to d through P. Also create line b as perpendicular bisector of Line Segment FP. Finally, point Q (the point creating locus line) is to be created as intersection of Lines p and b. Now
LocusEquation[Q,P]
will find and plot the exact equation of the locus. Note: See also Locus command.
Note:
- Works only for a restricted set of geometric loci, i.e. using points, lines, circles, conics. [Rays and line segments will be treated as (infinite) lines]
- If the locus is too complicated then it will return 'undefined'.
- The calculation is done using Gröbner bases, so sometimes extra branches of the curve will appear that were not in the original locus.
Following text is about a feature that is supported only in GeoGebra 5.0.
Note: In GeoGebra 5 and above a remote web server may be used to perform the calculation (this can be disabled by using command line option --singularWS=enable:false ). |