Inequality Evaluator

This shows how to use inqualities in a problem.

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Complete Code

Download file: InequalityEvaluators.pg

POD for Macro Files

See Also

PG problem file

Explanation

DOCUMENT();
loadMacros('PGstandard.pl', 'PGML.pl', 'contextInequalities.pl',
  'PGcourse.pl');

Preamble

These standard macros need to be loaded. 
Context("Inequalities-Only");
Context()->variables->add(y=>"Real");
# Context()->constants->add(EmptySet => Set());
# Context()->flags->set(noneWord=>"EmptySet");
# Context()->flags->set(ignoreEndpointTypes=>1);

# f(x) = x^2 - 16 on -1 <= x <= 5
$f = Formula("x^2 - 16");

$range = Compute("-16 <= y <= 9");

Context()->variables->remove("x");

Setup

Using Context('Inequalities-Only'), if the student enters the inequality -16 <= y <= 9 their answer will be marked correct, but the equivalent interval [-16,9] would be incorrect. If we had used Context(‘Inequalities’) instead, both the inequality and the interval would be marked correct.

Uncommenting the lines containing EmptySet creates an empty set as a named constant and uses that name.

Uncommenting Context()->flags->set(ignoreEndpointTypes=>1); would also mark the student answers -16 < y < 9 or -16 <= y < 9 or -16 < y <= 9 correct.

BEGIN_PGML
What is the range of
[`y = f(x) = [$f] `] on the domain [` -1 \leq x \leq 5 `]?


Range: [___]{$range}

Enter your answer using inequalities (not intervals).
END_PGML

Statement

This is the problem statement in PGML. 
BEGIN_PGML_SOLUTION
Solution explanation goes here.
END_PGML_SOLUTION

ENDDOCUMENT();

Solution

A solution should be provided here.