Math & Science ⇒ Use special character as a variable in a formula

[3102]

If i write $t=a$ in LaTex, I get "t = a". If I write $t=?$ I get "t =?" but I want to get "t = ?". The ? shall have the same distance from the equals sign as any other variable or letter. Is there a way to to treat the "?" the same way as any other letter in a formula?

To make clear how $t=a$ and t=? look like, I have added a screenshot.

[Johannes_B]

A quick and dirty hack would be to set the space by hand.

Code: Select all

\documentclass{article}
\usepackage{mathtools}
\newcommand{\iswhat}{\;?}
\begin{document}
$t=a$\par
$t=?$\par
$t=\iswhat$
\end{document}

[esdd]

Other possibilities are

Code: Select all

$t=\mathord{?}$

and

Code: Select all

$t={}?$