Attachments: If you need to send an attachment, you won't be able to use our web form. Instead, send an email message with your name, email address, your question (indicating where you are stuck on the problem) and the attachment to . Do not send executable files - we automatically filter these out. Word processing documents (.rtf, .doc) and photos or diagrams (in .gif, .png, .jpg) are fine.

Note: if you email us, please include [QQ] in the subject line (yes, include the square brackets too) or your message might not get through our spam filter.

Equations: Some equations are nearly impossible to type into a web form or an email message body. When that is the case, you will have to describe it as best you can in words or - if you know how to type the equation into some other software (such as the equation editor in Microsoft Word), you can type it in there and then send the word document as an attachment in an email message. If you need to draw a diagram, save it as a graphics file (preferably a .gif, .jpg or .png) and attach to an email message and send it to us (see above).

Here are a few simple guidelines for typing in equations into the web form or an email message:

1) Use the ^ sign to indicate an exponent. For example, to enter the equation:

2) When entering fractions, it's usually a good idea to put in extra parentheses to be clear what are the numerator and denominator expressions. For example, to enter the expression:

Often, people forget the parentheses and so they are asking different questions from what they think they are asking.