DisableFunctions1
Disabling Functions so Students Must Simplify Answers
This PG code shows how to disable all functions and restrict student answers to fractions.
 File location in OPL: FortLewis/Authoring/Templates/Trig/DisableFunctions1.pg
 PGML location in OPL: FortLewis/Authoring/Templates/Trig/DisableFunctions1_PGML.pg
PG problem file  Explanation 

Problem tagging: 

DOCUMENT(); loadMacros( "PGstandard.pl", "MathObjects.pl", "AnswerFormatHelp.pl", "contextFraction.pl", ); TEXT(beginproblem()); 
Initialization: 
Context("FractionNoDecimals"); # Prevent pi from becoming 3.1415... and cos(pi) from # becoming 1. Context()>constants>set(pi => {keepName => 1}); $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 reenable the
Note that 
Context()>texStrings; BEGIN_TEXT Enter your answers as simplified fractions. $BR $BR \( $f1 = \) \{ ans_rule(20) \} \{ AnswerFormatHelp("fractions") \} $BR $BR \( $f2 = \) \{ ans_rule(20) \} \{ AnswerFormatHelp("fractions") \} END_TEXT Context()>normalStrings; 
Main Text: 
$showPartialCorrectAnswers = 1; ANS( $answer1>cmp() ); ANS( $answer2>cmp() ); 
Answer Evaluation: 
Context()>texStrings; BEGIN_SOLUTION ${PAR}SOLUTION:${PAR} Solution explanation goes here. END_SOLUTION Context()>normalStrings; COMMENT('MathObject version.'); ENDDOCUMENT(); 
Solution: 