** Using WeBWorK **

Thanks for your help.

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Davide

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To this:

1. While viewing the problem click "Edit this problem" link^(you have to have instructor privileges to see this.)

2. Now that you are on the editor page you will see a row of links, the right most one will say "report problem bugs".

3. Clicking on this will take you to bugzilla. If this is your first time reporting the bug, there is a short setup sequence because bugzilla needs to know who you are in order to record the bug. It will ask you to enter your email. It will then email you a password. Once you are signed up with bugzilla you can change your password to something easy to remember. (This only happens the first time, after that you can enter your email address and password to login, or if you always use the same computer a cookie will be saved automatically and you won't have to do anything -- you will be taken straight to bugzilla.)

4. Once in bugzilla fill out a description of the problem. The address of the problem and the seed used which produces the error have been entered for you automatically. (If the PG problem is one you created and is not in a library you should include the code at the end of your entry.)

5. That's it. This method has been particularly useful for bugs found in library problems -- we are slowly getting rid of them all as the bug reports come in from across the country.

--Mike

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Here is the code:

DOCUMENT();

# Load whatever macros you need for the problem
loadMacros(PG.pl,
PGbasicmacros.pl,
PGchoicemacros.pl,
PGanswermacros.pl,
PGauxiliaryFunctions.pl,
PGgraphmacros.pl,
);

## Do NOT show partial correct answers
$showPartialCorrectAnswers = 0;
$a=random(2,9);
$b=random(2,9);
$c=$a*$a;
$soln="($b/$a)*arcsec(x/$a)";
TEXT(beginproblem());

BEGIN_TEXT

Integrate:

\[\int\frac{$b,dx}{x\sqrt{x^2-$c}}\]

\{ans_rule()\}+C
END_TEXT

ANS(fun_cmp($soln,mode=>"antider",vars=>"x"));

ENDDOCUMENT();

thanks for any help you can give. I will post a bug as soon as I am sure it is one and not stupidity on my part.

S.M.

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The default domain for checking functions is (0,1). In your case arcsec() has a domain that lies in the range (1, infinity)

Try this line:

ANS(fun_cmp($soln,mode=>"antider",vars=>"x",domain=>[2,5]));

The clue was the error message: "Can't generate enough valid points for comparison" which indicates not enough points were in the domain of the function.

Hope this helps.

-- Mike

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As I suspected, a stupid error :-). I am trying to save time by using other questions as a pattern for my own instead of reading the manual. That never seems to work in practice.

Thanks for your kind help.

S.M.

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