# RowOperations1

## Row Operations

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

PG problem file Explanation

Problem tagging:

DOCUMENT();
"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();