<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Arial",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Arial",sans-serif;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:"Arial",sans-serif;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoPlainText">Hi all!<o:p></o:p></p>
<p class="MsoPlainText"><span style="color:black">I've found a strange issue in some problems requiring formula response.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">I have a simple question to enter the formula for the resonant frequency.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">An example of correct answer is (in other variations the formula could be a bit more complex than this one)<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">1/(2*pi*sqrt(L*C))<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">The correct solution is checked by sampling L and C values.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">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:<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><img width="429" height="119" id="Picture_x0020_1" src="cid:image003.jpg@01D5A05B.449F5B20"></span><span style="color:black"><o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">But when I press submit, I got the response:<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">“unable to understand formula”<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">By experimenting with this, I found that the issue happens because of “pi” being a part of the answer.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">If pi is replaced with 3.141, everything would work.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">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.
<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Why is this happening? Apparently LON-CAPA knows what “pi” means because it displays it correctly.<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Thanks!<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black">Grigory<o:p></o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
<p class="MsoPlainText"><span style="color:black"><o:p> </o:p></span></p>
</div>
</body>
</html>