# Normal font in equations quoted with Dollar

Text or formula within ${---}$ and in itemize are in italic. How to convert into normal?? I have used \text and \mathrm but it's not working. Anyone please find solution for this following code:

\begin{itemize}
\item {\ Y(t)\  =\ A\ Sin($2\pi f_{in}t)$} \newline
$\implies{Slope, s\ =\ \frac{dy}{dt}\ = 2\pi f_{in}Acos(2\pi f_{in}t)]}$
\item{$Suppose \ n=10\ bits\ and\ t_{s}=1ns$}
\end{itemize}
• Welcome @chaisrav, please provide a minimum working example. (This means, include all the stuff before \begin{document}, so that we have a better idea exactly what's going on with your code.) Commented Nov 27, 2018 at 6:29

I think that \text is an amsmath command.

Try adding \usepackage{amsmath} to your preamble (before \begin{document}, then try using \text{} again.

Also note that for functions like cos, you really want to be them to be operators. For common functions, you can achieve this just by using \cos instead. This will put cos in upright text, and as a bonus, adjust the spacing.

Also, you shouldn't be using \ (backslash space) inside maths mode. Spacing should be automatic. (Maths mode does destroy spaces, but this is usually a good thing.)

Alternatively, just don't use  when you want text.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{itemize}
\item $Y(t) = A \sin(2\pi f_{in}t)$ \\
$\implies$ Slope, $s = \frac{dy}{dt} = 2\pi f_{in}A \cos(2\pi f_{in}t)$
\item Suppose $n=10$ bits and $t_{s}=1ns$
\end{itemize}
\end{document}

I very strongly recommend The Not So Short Introduction to LaTeX 2ε. Save it to your computer! I still reference this document regularly.