View of /trunk/webwork-modperl/doc/parser/problems/sample13.pg

    1 ##########################################################
    2 #
    3 #  Example showing how to use the built-in answer checker for parsed values.
    4 #
    5 
    6 DOCUMENT();        # This should be the first executable line in the problem.
    7 
    8 loadMacros(
    9   "PGbasicmacros.pl",
   10   "PGanswermacros.pl",
   11   "Parser.pl",
   12   "parserUtils.pl",
   13 );
   14 
   15 TEXT(beginproblem());
   16 
   17 ##########################################################
   18 #
   19 #  The setup
   20 #
   21 
   22 Context("Interval");
   23 
   24 $a = non_zero_random(-5,5,1);
   25 $f = Formula("(x^2+1)/(x-$a)")->reduce;
   26 $R = Formula("(-inf,$a),($a,inf)")->eval;
   27 
   28 ##########################################################
   29 #
   30 #  The problem text
   31 #
   32 
   33 Context()->texStrings;
   34 BEGIN_TEXT
   35 
   36 Suppose \(\displaystyle f(x) = $f\).
   37 $PAR
   38 Then \(f\) is defined on the intervals \{ans_rule(30)\}.
   39 $PAR
   40 ${BCENTER}
   41 ${BSMALL}
   42 To enter more than one interval, separate them by commas.$BR
   43 Use ${LQ}${BTT}infinity${ETT}${RQ} for ${LQ}\(\infty\)${RQ} and
   44 ${LQ}${BTT}-infinity${ETT}${RQ} for ${LQ}\(-\infty\)${RQ}.
   45 ${ESMALL}
   46 ${ECENTER}
   47 
   48 END_TEXT
   49 Context()->normalStrings;
   50 
   51 ###########################################################
   52 #
   53 #  The answer
   54 #
   55 
   56 ANS($R->cmp);
   57 $showPartialCorrectAnswers = 1;
   58 
   59 ###########################################################
   60 
   61 ENDDOCUMENT();        # This should be the last executable line in the problem.