ImplicitPlane

From WeBWorK_wiki
Revision as of 00:58, 25 January 2010 by Pearson (talk | contribs)
Jump to navigation Jump to search

Planes Defined Implicitly

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

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);

Setup: 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;

Main Text: Self-explanatory.

ANS(ImplicitPlane($A,$N)->cmp);
$showPartialCorrectAnswers = 1;

ENDDOCUMENT();

Answer Evaluation: Just specify a point $A and a normal vector $N.

Problem Techniques Index