** Using WeBWorK **

Specifically, if you try the following pg file, I get errors, but it works fine if the the TEXT(EV2(<<EOT)); for is used:

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

loadMacros(
PG.pl,
PGbasicmacros.pl,
PGchoicemacros.pl,
PGanswermacros.pl,
PGauxiliaryFunctions.pl
);

TEXT(&beginproblem);
$showPartialCorrectAnswers = 1;

$a1 = random(1,4,1);

$b1 = random(2,5,1);

$x1 = random(1,5,1);

$m1 = $b1/(2*($a1+$b1*$x1)**.5);

BEGIN_TEXT

Let \[ f(x) = \sqrt { $a1 + $b1 x } \]

$PAR

\( f'( $x1 ) = \) \{ans_rule(20) \}

$BR

END_TEXT

$ans = $m1;

&ANS(std_num_cmp($ans));

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

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This works:

TEXT(EV2(<<EOT));

But this fails:

TEXT(EV2(<<'EOT'));

Note the single quotes.

I'm confused.

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BEGIN_TEXT is exactly equivalent to

TEXT(EV3(<<'END_TEXT'));

The details are given at http://webhost.math.rochester.edu/webworkdocs/docs/pglanguage/tutorial/problemtext

The difference between

TEXT(EV2(<<EOT));
TEXT(EV3(<<'EOT'));

is that in the first case the $variables are evaluated first, before anything else. In the second, the $variables are evaluated after the \{ .... \} code has been evaluated.

See also http://webwork.math.rochester.edu/docs/docs/pglanguage/pod/pgbasicmacros.html#ev2

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Offhand, I don't see why BETIN_TEXT/END_TEXT should fail above. What error messages are generated?

John

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Are these differences the same as for the constructions for EV3 below :

SOLUTION(EV3(<<'EOT'));

and

SOLUTION(EV3(<<EOT));

?????????????

Thanks! Blake

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If you are interested, I am happy to post the exact files and details of all the errors, but my guess is that everyone's time is better spent elsewhere.

In any case, here is the example of one of the errors:

% ERROR in :EV3, PGbasicmacros.pl:  % There is an error occuring in the following code: 

Solution:

a) The point crosses the x-axis when the y-coordinate is zero.
This happens when .
Plugging these in: .
% % Unrecognized escape p passed through at (eval 18125) line 1.
% % %

In any case, thanks to those who pointed me in the right direction!!

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For the original problem (which I have been unable to reproduce here.) Do you get the same result if you replace BEGIN_TEXT by

TEXT(EV3(<<'END_TEXT'))

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EV2 is meant to be used with double quotes:

EV2(<<"EOT")); or EV2(<<EOT)

(no quotes defaults to double quotes)

while EV3 is not:

EV3(<<'EOT'));

If you use double quotes with EV3 then the $variables will be interpolated (evaluated) first. If you use single quotes with EV2 then there is a good chance that the $variables will not be interpolated at all.

For many simple problems the two produce the same results, since the order of interpolating, vs evaluating the \{ \} segments doesn't matter.

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