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

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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: 9444
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:

1. \documentclass{article}
2. \usepackage{amsmath}
3. \DeclareMathOperator\app{app}
4. \begin{document}
5. \begin{equation}
6. F = \left\lbrace
7. \begin{array}{ll}
8. F_{\app} \, \mu_{k} \sin(v) & \text{ if } v > 0, \\
9. F_{\app} & \text{ if } v = 0
10. \text{ and } F_{\app}\leq F_{\app} \, \mu_{s}
11. \end{array}
12. \right.
13. %\label{RRRR}
14. \end{equation}
15. \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 522 times

Stefan

mas
Posts: 220
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:
1. \documentclass{article}
2. \usepackage{amsmath}
3. \DeclareMathOperator\app{app}
4. \begin{document}
5. \begin{equation}
6. F =
7. \begin{cases}
8. F_{\app} \, \mu_{k} \sin(v) & \text{ if } v > 0, \\
9. F_{\app} & \text{ if } v = 0
10. \text{ and } F_{\app}\leq F_{\app} \, \mu_{s}
11. \end{cases}
12. %\label{RRRR}
13. \end{equation}
14. \end{document}

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