ImplicitPlane
Planes Defined Implicitly: PG Code Snippet
This code snippet shows the PG code to evaluate answers that are planes defined implicitly by an equation.
| PG problem file | Explanation | 
|---|---|
DOCUMENT(); loadMacros( "PGstandard.pl", "MathObjects.pl", "parserImplicitPlane.pl", "parserVectorUtils.pl", "PGcourse.pl", ); TEXT(beginproblem);  | 
 
Initialization: In particular, we need to include the   | 
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;
#  The points A, B and C
$A = non_zero_point3D();
$B = Point($A + $AB);
$C = Point($A + $AC);
 | 
 Set-up: Create points and vectors. Make sure that the vectors are not parallel.  | 
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;
 | 
 Question: self-explanatory.  | 
ANS(ImplicitPlane($A,$N)->cmp); $showPartialCorrectAnswers = 1; ENDDOCUMENT();  | 
 Answer Evaluation: Just specify a point $A and a normal vector $N.  |