We are using an old problem from the problem library. It is

*Rochester/setLimitsRates2Limits/ur_lr_2_11.pg*

When students submitted their answers, they'll encounter a warning sign. With further investigation, I found that the second part of the answer (a string) won't show if I preview my answer even though the problem still accepts it. How can I fixed it?

Thanks,

Dave

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Here is the warning sign:

The evaluated answer is not an answer hash HASH(0xbe8b7698): |HASH|.

## WeBWorK Warnings

WeBWorK has encountered warnings while processing your request. If this occured when viewing a problem, it was likely caused by an error or ambiguity in that problem. Otherwise, it may indicate a problem with the WeBWorK system itself. If you are a student, report these warnings to your professor to have them corrected. If you are a professor, please consult the warning output below for more information.

### Warning messages

`HASH(0xbe8b7698) is not an answerHash in queue evaluator`

`HASH(0xbe8b7698) is not an answerHash in queue post_filter`

I am also posting the code here in case anyone can not find the problem.

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*#DESCRIPTION*

*#KEYWORDS('limits', 'sequences', 'squeeze theorem')*

*# Find limits using the squeeze theorem*

*#ENDDESCRIPTION*

*##KEYWORDS('Calculus')*

*##Tagged by ynw2d*

*##DBsubject('Calculus')*

*##DBchapter('Limits and Derivatives')*

*##DBsection('Calculating Limits Using the Limit Laws')*

*DOCUMENT(); # This should be the first executable line in the problem.*

*loadMacros("PG.pl",*

*"PGbasicmacros.pl",*

*"PGchoicemacros.pl",*

*"PGanswermacros.pl",*

*"PGauxiliaryFunctions.pl");*

*$a = random(2,4,1);*

*$b = random(6,8,1);*

*$c = random(-6,-2,1);*

*# coefficients of quadratic x^2 + a1x + a2 passing through c at a*

*$a1 = $b-$a;*

*$a2 = -$a*$b+$c;*

*# coefficients of line b1x +b2 passing through c at a and tangent to quadratic above.*

*$b1 = $a + $b;*

*$b2 = -$a*($a +$b) + $c;*

*TEXT(beginproblem());*

*$showPartialCorrectAnswers=1;*

*BEGIN_TEXT*

*If \[ ${b1}x +$b2 \le f(x) \le x^2 + ${a1}x + $a2 \] determine*

*\(\displaystyle \lim_{x\to $a} f(x) \) = \{ans_rule(20) \}*

*$PAR*

*What theorem did you use to arrive at your answer? $BR*

*\{ ans_rule(50) \}*

*END_TEXT*

*$ans_eval = sub { my $in = shift;*

*$in = lc($in);*

*my $score;*

*if ( $in =~ /squeeze/ or $in =~ /pinch/ or $in =~/sandwich/) {*

*$score = 1;*

*} else {*

*$score = 0;*

*}*

*my $ans_hash = { score => $score,*

*correct_ans => "The Squeeze theorem",*

*student_ans => $in,*

*ans_message => ($score) ? '' : "Hint: Look thorugh the end of section 2.3",*

*};*

*$ans_hash;*

*};*

*ANS(num_cmp($c), $ans_eval);*

*ENDDOCUMENT(); # This should be the last executable line in the problem.*

*-----------------------------------------------------------------------------------------------------------------*