DisableFunctions1

Disabling Functions so Students Must Simplify Answers

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This PG code shows how to disable all functions and restrict student answers to fractions.

• PGML location in OPL: FortLewis/Authoring/Templates/Trig/DisableFunctions1_PGML.pg

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PG problem file	Explanation
Problem tagging data	Problem tagging:
DOCUMENT(); loadMacros( 'PGstandard.pl', 'MathObjects.pl', 'contextFraction.pl', 'PGML.pl', 'PGcourse.pl' ); TEXT(beginproblem());	Initialization: The contextFraction.pl is loaded since we used the Fraction-NoDecimals</text> context.
Context('Fraction-NoDecimals'); # Prevent pi from becoming 3.1415... and cos(pi) from # becoming -1. Context()->constants->set(pi => {keepName => 1}); # The next context changes are not necessary to # prevent cos(pi) from becoming -1, but they cannot hurt. Context()->flags->set( reduceConstants=>0, reduceConstantFunctions=>0 ); $f1 = Formula('cos(pi)'); $f2 = Formula('sin(pi/3)'); Context()->functions->disable('All'); Context()->functions->enable('sqrt'); $answer1 = Compute('-1'); $answer2 = Compute('sqrt(3)/2');	Setup: We choose a context that requires fractions as answers and does not allow decimals. After constructing the formulas involving trig functions, we disable all functions and re-enable the sqrt() function. This means that students are allowed to type in fractions and square roots, but not much else (e.g., they'll get an error message if they type in a trig function). Note that $f1 and $f2 are MathObject Formulas, which do not get reduced since pi is set to keep its name. If $f1 and $f2 used Compute instead, then the results would be -1 and 0.866... instead of cos(\pi) and sin(\pi/3) as desired.
BEGIN_PGML Enter your answers as simplified fractions. + [` [$f1] = `] [_____________]{$answer1} + [` [$f2] = `] [_____________]{$answer2} [@ helpLink('fractions') @]* END_PGML	Main Text:
BEGIN_PGML_SOLUTION The cosine of an angle is zero when the angle is an integer multiple of \( \pi \). END_PGML_SOLUTION ENDDOCUMENT();	Solution:

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