I believe the unexpected ess-zett shows up because \rm
is not a command that takes an argument but, instead, a switch: all subsequent material (until either some other font-changing command is encountered or until the current (math) environment ends) is instructed to show up in "roman" mode. It just so happens that the text-mode glyph that's in the same spot of the respective font table where \pi
would be in the math mode font table happens to be the ess-zett.
Rather than using \rm
-- which is a holdover from (Plain) TeX and is only barely supported by LaTeX -- you really should use either the \text
macro of the amsmath
package (which you're already loading anyway, it would appear) and/or create a few dedicated macros, such as
\newcommand\rad{\text{rad}} % `\text` is a macro provided by the amsmath package
\newcommand\second{\text{sec}}
\newcommand\cm{\text{cm}}
and then write
\begin{align*}
&= (100\,\rad/\second)(20\,\cm)(\sin(\pi/2))
\end{align*}
which will give you the output you'd expect to get. (Aside: You should probably write "s" rather than "sec" for second...)
Addendum Better still, consider loading the siunitx package, e.g., with the instruction
\usepackage[mode=text,per-mode=symbol]{siunitx}
(as well as, of course, the amsmath
, eulervm
, and bookman
packages). Then you could write the expression in question as
\begin{align*}
&= (\SI{100}{\radian\per\second})(\SI{20}{\centi\meter})(\sin(\pi/2))
\end{align*}
and you'd automatically get a proper "thin-space" between the numerals and the associate units.
Finally, you mention encountering some problems with \mathbf
; that works for (Latin) letters but not for other symbols (including various Greek letters). Use \boldsymbol
for the latter symbols.
Best Answer
You can find a number of font alternatives that get pretty close to your sample at the LaTeX Font Catalogue, Calligraphical and Handwritten Fonts. Here are some options (although some are of questionable typographically technical quality, i.e. not vectorized fonts that look pixel-y):
Lukas Svatba has even more options. For information on how to implement a particular font, see the respective page in the Font Catalogue.