## WeBWorK Problems

### Operatorname not defined for arccot(x)

by Brittni Lorton -
Number of replies: 5

I have a weird issue. This problem is giving an error of 'operator name not defined' when one enters the answer using arccot(x). It has no issues with acot(x), or with cot^-1(x), but for some reason it isn't accepting the arccot(x). Any advice?

Working code is:

DOCUMENT();

loadMacros(

"PGstandard.pl",

"MathObjects.pl",

"AnswerFormatHelp.pl",

"PGML.pl",

"PGcourse.pl",

"contextFraction.pl",

"parserFormulaUpToConstant.pl"

);

TEXT(beginproblem());

$showPartialCorrectAnswers = 1;$a = random(0,5,1);

$b = random(5,10,1);$c = random(2,9,1);

Context("Numeric");

Parser::Number::NoDecimals();

$ans = Compute("(1/$c)*(arctan $b - arctan$a)")-> reduce;

BEGIN_PGML

Evaluate the following definite integral.

Your answer must be exact.

[ \displaystyle \int_{[$a]}^{[$b]} \frac{1}{[$c]+[$c] x^2}  \, dx =][______________________________________]{\$ans} [@ AnswerFormatHelp("numbers") @]*

END_PGML

ENDDOCUMENT();

Picture of error is attached.

In reply to Brittni Lorton

### Re: Operatorname not defined for arccot(x)

by Danny Glin -
The picture doesn't appear to have come through.

What version of WeBWorK are you running? I just tried this with 2.17 and it accepts answers involving arccot for me.
In reply to Danny Glin

### Re: Operatorname not defined for arccot(x)

by Brittni Lorton -

Here is another try at adding the picture:

We are using version 2.15

In reply to Brittni Lorton

### Re: Operatorname not defined for arccot(x)

by Glenn Rice -

The issue you are seeing was a MathQuill issue. That was fixed in either 2.16 or 2.17 (I am not sure which right now, and am not where I can look it up either).

In reply to Glenn Rice

### Re: Operatorname not defined for arccot(x)

by Brittni Lorton -
Gotcha. I wont worry about changing any code then and I'll just wait until we update. Thanks!
In reply to Brittni Lorton

### Re: Operatorname not defined for arccot(x)

by Glenn Rice -
This was fixed in MathQuill for WeBWorK 2.16 for future reference.