# Problem defining function

I'm a little bit of a rookie in using latex. I want to define a function using latex and I'm struggling trying to do that, the function is :

f:A->A
x->(f1(x),f2(x))


I've tried something but I know it's definitely not correct. Can you help me please?

$f$ : $B_k$ $\longrightarrow$ $B_k$\\
$x$ &\mapsto$f$$f_1\(x),f_2(x)$$  • – moewe Apr 2 '18 at 20:45 ## 2 Answers You can use this, if it's in-line maths: $\begin{aligned}[t] f\colon A &\longrightarrow A\\
x &\longmapsto \bigl(f_1(x),f_2(x)\bigr)
\end{aligned} If it is a displayed equation, use \begin{align*} ... \end{align*} ine the place of \begin{aligned}[t] ... \end{aligned} I would not use an aligned approach in an inline set. Here is something your can work with: \documentclass{memoir} \usepackage{amsmath} \begin{document} Let us consider the function \begin{align*} f\colon A &\to A,\\ x &\mapsto \big(f_1(x), f_2(x)\big). \end{align*} Saepe at quas accusamus molestiae possimus consequatur vitae. For an inline attempt, I would go withf\colon A \to A,\, x \mapsto \big(f_1(x), f_2(x)\big)\$.
Saepe at quas accusamus molestiae possimus consequatur vitae.
\end{document}


Seriously, you should consider some basic training in TeX, for example https://ctan.org/pkg/lshort-english, https://ctan.org/pkg/short-math-guide or https://ctan.org/pkg/latex-amsmath.

• indeed, and i will surely do so, thanks for the help – Ali Az Apr 2 '18 at 18:17