RowOperations1

From WeBWorK_wiki
Revision as of 15:26, 14 June 2015 by Paultpearson (talk | contribs) (PGML example link)
Jump to navigation Jump to search

Row Operations

Click to enlarge

This PG code shows how to ask students to compute the result of elementary row operations.


Templates by Subject Area

PG problem file Explanation

Problem tagging data

Problem tagging:

DOCUMENT();
loadMacros(
"PGstandard.pl",
"MathObjects.pl",
"PGcourse.pl",
);
$showPartialCorrectAnswers = 0;
TEXT(beginproblem()); 

Initialization:

Context('Matrix');

do {

$A = Matrix([
[non_zero_random(-5,5,1),non_zero_random(-5,5,1)],
[non_zero_random(-5,5,1),non_zero_random(-5,5,1)],
[non_zero_random(-5,5,1),non_zero_random(-5,5,1)],
]);

} until (($A->row(1) != $A->row(2)) && 
         ($A->row(1) != $A->row(3)) && 
         ($A->row(2) != $A->row(3)));

$k = random(2,9,1);

$op = "R_{1} + $k R_{2} \rightarrow R_{1}";

$answer = Matrix([
  $A->row(1) + $k*($A->row(2)),
  $A->row(2),
  $A->row(3),
  ]);

Setup: Construct a matrix with three distinct rows. Create a string $op of Tex code that describes the row operation. Use $A->row(i) to extract the ith row of the matrix A as a MathObject. Use $A->row(1) + $k*($A->row(2)) to perform the row operation and place it into the first row of the answer matrix.

Context()->texStrings;
BEGIN_TEXT
Give the result of applying the row operation \( $op \) to the given matrix.
$BR
$BR
\( $A {\displaystyle\mathop{\longrightarrow}^{$op}} \)
\{ $answer->ans_array \}
END_TEXT
Context()->normalStrings;

Main Text:


ANS( $answer->cmp() );

COMMENT('MathObject version.');

ENDDOCUMENT();

Answer Evaluation:

Templates by Subject Area