[LON-CAPA-users] Formula response won't recognize "pi"

SIMIN, GRIGORY SIMIN at engr.sc.edu
Thu Nov 21 11:03:15 EST 2019

Hi all!

I've found a strange issue in some problems requiring formula response.

I have a simple question to enter the formula for the resonant frequency.

An example of correct answer is (in other variations the formula could be a bit more complex than this one)


The correct solution is checked by sampling L and C values.

When I am entering the answer, I can see that LON-CAPA recognizes it because it displays the formatted formula as I am entering it:

[cid:image003.jpg at 01D5A05B.449F5B20]

But when I press submit, I got the response:

“unable to understand formula”

By experimenting with this, I found that the issue happens because of “pi” being a part of the answer.

If pi is replaced with 3.141, everything would work.

But it feels weird asking students to enter 3.141 instead of pi; besides, I don’t even want to give them a hint that pi is a part of the answer.

Why is this happening? Apparently LON-CAPA knows what “pi” means because it displays it correctly.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.lon-capa.org/pipermail/lon-capa-users/attachments/20191121/902989ac/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 8375 bytes
Desc: image003.jpg
URL: <http://mail.lon-capa.org/pipermail/lon-capa-users/attachments/20191121/902989ac/attachment-0001.jpg>

More information about the LON-CAPA-users mailing list