## LaTeX forum ⇒ Math & Science ⇒ adding tabular in equation/math enviroment

Information and discussion about LaTeX's math and science related features (e.g. formulas, graphs).
afa0011
Posts: 8
Joined: Mon Sep 24, 2018 6:18 pm

### adding tabular in equation/math enviroment

can you help me fith the following expression please ?

\begin{equation}
F=\left\lbrace
\begin{tabular}{ll}
$F_{app}\mu_{k}\sin (v)$ & $if \quad v>0$, \\
$F_{app}$ & if$\quad v=0 \quad and \quad F_{app}\leq F_{app} \mu_{s}$,
\end{tabular}
\right
%\label{RRRR}
\end{equation}

Stefan Kottwitz
Posts: 9557
Joined: Mon Mar 10, 2008 9:44 pm
Hi!

There's a math equivalent to tabular, it's array. Here is how I would do it:

\documentclass{article}\usepackage{amsmath}\DeclareMathOperator\app{app}\begin{document}\begin{equation}  F = \left\lbrace        \begin{array}{ll}           F_{\app} \, \mu_{k} \sin(v) & \text{ if } v > 0, \\           F_{\app} & \text{ if } v = 0                          \text{ and } F_{\app}\leq F_{\app} \, \mu_{s}        \end{array}      \right.%\label{RRRR}\end{equation}\end{document}

I defined an operator, since it that index looks like an operator (that's usually written in upright shape) and not like a product of a, p, and p. Furthermore, I treated text (if, and) as text. What do you think? equation.png (9.99 KiB) Viewed 624 times

Stefan

mas
Posts: 222
Joined: Thu Dec 04, 2008 4:39 am
Just a small change to Stefan's answer. I suggest the use of {cases} for typesetting the equation. Here is the code:
\documentclass{article}                                                                                                                                                                       \usepackage{amsmath}                                                                                                                                                                          \DeclareMathOperator\app{app}                                                                                                                                                                 \begin{document}                                                                                                                                                                              \begin{equation}                                                                                                                                                                                F =                                                                                                                                                                                             \begin{cases}                                                                                                                                                                                    F_{\app} \, \mu_{k} \sin(v) & \text{ if } v > 0, \\                                                                                                                                           F_{\app} & \text{ if } v = 0                                                                                                                                                                                 \text{ and } F_{\app}\leq F_{\app} \, \mu_{s}                                                                                                                               \end{cases}                                                                                                                                                                               %\label{RRRR}                                                                                                                                                                                 \end{equation}                                                                                                                                                                                \end{document}