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I want to write three equations in the \begin{align}\end{align}
\begin{aligned}
\min_{x \in \mathbb{R}} &f_i(x), & \qquad \left(i=1,\,2,\,\,\dots,\,M\right),\\
\text{sujeita a } &\phi_j(x)=0,& \left(i=1,\,2,\,\,\dots,\,J\right),\\
&\psi_k(x)\leq 0, & \left(i=1,\,2,\,\,\dots,\,K\right),
\end{aligned}
\end{align}
This is my output:
But I want that $f_i(x)$ be left aligned with $\phi_j(x)=0,$ and $\psi_k(x)\leq 0,$ Any suggestion? I will be very greatful.
Thank in advance
You appear to have cropped out the equation number align would have provided - if you are looking for just one equation number, you can uncomment the commented lines here and comment out the alignat ones - or you can have the three equation numbers with alignat. (The excessive spacing in the code is for readability purposes here - no need for it in your actual document)
The extra braces around the min are to show it aligned with the text below - again, for illustrative purposes - I'd be inclined to agree with hesham that this may not be the best alignment for this display.
I have left the \left( and \right) on the first line to highlight the undesirable effect they have on the spacing. Please avoid them if possible.
\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}
%\begin{align}
%\begin{aligned}
\begin{alignat}{3}
&{\min_{x \in \mathbb{R}}} &\quad &f_i(x), &\quad &\left(i=1,\,2,\,\,\dots,\,M\right),
\\
&\text{sujeita a } &\quad &\phi_j(x)=0, &\quad &(i=1,\,2,\,\,\dots,\,J),
\\
& & &\psi_k(x)\leq 0, &\quad &(i=1,\,2,\,\,\dots,\,K),
\end{alignat}
%\end{aligned}
%\end{align}
\end{document}
\documentclass{..}?
– Sebastiano
Aug 22 '20 at 11:20
The tool of choise to have full control on the alignment columns spacing is alignat:
\documentclass{article}
\usepackage{amsmath, amssymb}
\begin{document}
\begin{alignat*}{3}
&\min_{x \in \mathbb{R}}&&f_i(x), & (i & =1,2,\ldots, M),\\
&\text{sujeita a }&&\phi_j(x)=0, & (j & =1,2,\ldots, J), \\
&&\quad&\psi_k(x)\leq 0, &\qquad (k & =1,2,\ldots K),
\end{alignat*}
\end{document}
Something of similar using flalign? I will use an array or alignat enviroments.
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\begin{document}
\begin{flalign}
&\min_{x \in \mathbb{R}}&&f_i(x),\quad (i=1,2,\ldots, M),&&\notag\\
&\text{sujeita a }&&\phi_j(x)=0,\quad (i=1,2,\ldots, J),&&\\
&&&\psi_k(x)\leq 0, \quad (i=1,2,\ldots K),&&\notag
\end{flalign}
\end{document}
Using alignat enviroment:
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\begin{document}
\begin{alignat*}{2}
&\!\min_{x \in \mathbb{R}} &\quad& f_i(x), \quad (i=1,2,\ldots, M),\\
&\text{sujeita a }& & \phi_j(x)=0, \quad (i=1,2,\ldots, J),\\
& & & \psi_k(x)\leq 0, \quad (i=1,2,\ldots K),
\end{alignat*}
\end{document}
alignedat within equation, you wouldn't need \notag. Also, on the first line, the last element should be aligned with the similar elements in the other two lines.
– barbara beeton
Aug 22 '20 at 0:01
My preference would go to alignedat:
\documentclass{article}
\usepackage{amsmath,amssymb}
\begin{document}
\begin{equation}
\begin{alignedat}{3}
&\!\min_{x \in \mathbb{R}}
&\quad& f_i(x), &\qquad& (i=1,2,\dots,M),\\
&\text{sujeita a}
&\quad& \phi_j(x)=0, &\qquad& (i=1,2,\dots,J),\\
&
&\quad& \psi_k(x)\leq 0, &\qquad& (i=1,2,\dots,K),
\end{alignedat}
\end{equation}
\begin{equation}
\begin{alignedat}{3}
&\!\min_{x \in \mathbb{R}} f_i(x),
&\quad& &\qquad& (i=1,2,\dots,M),\\
&\text{sujeita a}
&\quad& \phi_j(x)=0, &\qquad& (i=1,2,\dots,J),\\
&
&\quad& \psi_k(x)\leq 0, &\qquad& (i=1,2,\dots,K),
\end{alignedat}
\end{equation}
\end{document}
In the second display, the objective function is not aligned with the bounds, which is more usual, I believe.
\minandf_i(x)should be aligned separately. – hesham Aug 21 '20 at 23:11