ImplicitPlane

This article has been retained as a historical document. It is not up-to-date and the formatting may be lacking. Use the information herein with caution.

This problem has been replaced with a newer version of this problem

Planes or Lines Defined Implicitly

This shows the PG code to evaluate answers that are planes or lines defined implicitly by an equation.

You may also be interested in EquationsDefiningFunctions

Problem Techniques Index

PG problem file	Explanation
DOCUMENT(); loadMacros( "PGstandard.pl", "parserImplicitPlane.pl", "parserVectorUtils.pl", "PGcourse.pl", ); TEXT(beginproblem());	Initialization: In particular, we need to include the parserImplicitPlane.pl macro file, which automatically loads MathObjects.pl.
Context("ImplicitPlane"); # Vectors in the plane $AB = non_zero_vector3D(); $AC = non_zero_vector3D(); while (areParallel $AB $AC) {$AC = non_zero_vector3D()} # The normal vector $N = cross $AB $AC; # or $N = $AB x $AC; # The points A, B and C $A = non_zero_point3D(); $B = Point($A + $AB); $C = Point($A + $AC); $answer = ImplicitPlane($A,$N);	Setup: Create points and vectors. Make sure that the vectors are not parallel. There are several other ways to define planes implicitly, which are explained at parserImplicitPlane.pl If the correct answer is a line in 2D space instead of a plane in 3D space, the only modification needed is to reduce the number of variables to two, which will modify error messages accordingly. Context("ImplicitPlane"); Context()->variables->are(x=>"Real",y=>"Real"); $answer = ImplicitPlane("y=4x+3");
Context()->texStrings; BEGIN_TEXT An implicit equation for the plane passing through the points \($A\), \($B\), and \($C\) is \{ans_rule(40)\}. END_TEXT Context()->normalStrings;	Main Text: Self-explanatory.
ANS( $answer->cmp ); $showPartialCorrectAnswers = 1; ENDDOCUMENT();	Answer Evaluation: Just specify a point $A and a normal vector $N.

Problem Techniques Index

• POD documentation: parserImplicitPlane.pl
• PG macro code: parserImplicitPlane.pl

• POD documentation: parserVectorUtils.pl
• PG macro code: parserVectorUtils.pl