The answer "ln(abs(x))" gives wrong answer when submit it

The sample question is attached

I am using Moodle 3.6

The answer "ln(abs(x))" gives wrong answer when submit it

The sample question is attached

I am using Moodle 3.6

Hello Ahmed,

Just change x={2:10} to x={2:3} and it works:

Thank you very much

Hi Dominique

I changed x as you posted but still not working

I changed x as you posted but still not working

It works only when I typed in the placeholder. If I click Fill in correct answer it does not work!! any way thanks a lot my problem solved

Hello Ahmed,

I'm sorry, actually I gave you the wrong answer. You can keep x={2:10} and C={2:10}, or better you can extend the checking interval and the number of checking points to say x={2:100} and C={-100:100}. The correct way is simply to set the "Grading criterion" to "Absolute error < 0.0000001" (or some other small number).

Hi Dominique

This works even for more complex (ln) functions thanks a lot,. But the problem with Fill in the correct answer, It changes the (ln) to (log) which is not acceptable in the input box.

Another question can we insert Greek letter like \beta in the answer place holder

This works even for more complex (ln) functions thanks a lot,. But the problem with Fill in the correct answer, It changes the (ln) to (log) which is not acceptable in the input box.

Another question can we insert Greek letter like \beta in the answer place holder

Hello Ahmed,

*But the problem with Fill in the correct answer, it changes the (ln) to (log) which is not acceptable in the input box.*

Don't worry too much about it. "Fill in correct responses" is only a preview for the teacher. It doesn't change anything
for students. Do not use 'Right answer' under 'Review options' in the quiz settings. Instead, make your own feedbacks.

The PHP function for the natural logarithm is "log", while in general mathematicians denote the natural logarithm by "ln". So, in the calculations you must use 'log', but with the 'Algebraic formula' answer type, you must use 'ln' to accommodate students in mathematics, physics, engineering, etc. who are more familiar with the 'ln' notation. Isn't it well done!

*Another question can we insert Greek letter like \beta in the answer place holder*

No, you must insert the name of a variable and the name of variables must be a string of alphanumeric characters (a-z, A-Z, 0-9 and _) that cannot begin with a
number or the underscore. See MoodleFormulas.org for more details.