Take the 2-minute tour ×
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It's 100% free, no registration required.

I want to align some equations on the left side in a document. And additionally I want to have some aligned text behind every equation. Also the equations need to be numbered. With the code below my goal is almost achieved. I just need to bring the text aligned to the right... How do I do that? Thanks

\documentclass[a4paper, 11pt]{book}
\usepackage{amsmath}
\begin{document}
\begin{flalign}
    &u_\mathrm{L} = L \cdot \frac{\text{d}i_\mathrm{L}}{\text{d}t} \quad(\text{Differentialform}) &\label{eq:2_19} \\
    &i_\mathrm{L} = \frac{1}{L} \cdot \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0) \quad (\text{Integralform}) &\label{eq:2_20}
\end{flalign}
\end{document}
share|improve this question

3 Answers 3

up vote 3 down vote accepted

... or just rearrange ampersands:

\documentclass[a4paper, 11pt]{book}
    \usepackage{amsmath}
\begin{document}
    \begin{flalign}
u_\mathrm{L}    &   = L \cdot \frac{\text{d}i_\mathrm{L}}{\text{d}t}       
    &       
                &   \text{(Differentialform)}       &       &   \\
i_\mathrm{L}    & = \frac{1}{L} \cdot \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0)     
    &       
                &   \text{(Integralform)}           &       &   
    \end{flalign}
\end{document} 
share|improve this answer

It's just a matter of using \mathllapfrom the mathtools package for (part of) the longest equation:

 \documentclass[a4paper, 11pt]{book}

\usepackage{mathtools}

\begin{document}

\begin{flalign}
& u_\mathrm{L} = L · \frac{\text{d}i_\mathrm{L}}{\text{d}t} & & \text{(Differentialform)} & & \label{eq:2_19} \\
& \mathrlap{i_\mathrm{L} = \frac{1}{L} · \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0) } & & \text{(Integralform)} & & \label{eq:2_20}
\end{flalign}

\end{document} 

enter image description here

share|improve this answer
    
I don't want the text all the way on the right side. I want the text to start on the same height. say \qquad behind the end of the longer equation. –  Dave Apr 12 at 20:57
    
Sorry, I misunderstood what you want. I'll modify my answer in a moment. –  Bernard Apr 12 at 21:42
    
@Dave: I modified my answer. Hope the spacing is correct for you. –  Bernard Apr 12 at 21:59
    
I got some conflict with the mathtools package. I will try your solution at some other point. The solution with rearranging the ampersands is the easiest solution I guess. –  Dave Apr 12 at 22:29
    
Strange… In my opinion, mathtools is one of the really fundamental packages for maths, as it extends amsmath (and corrects two bugs). –  Bernard Apr 12 at 22:45

You can use the [fleqn] option to the amsmath pacakge and and control the left indent via the \mathindent length:

enter image description here

Notes:

  • The showframe package was used just to show the page margins. It is not needed in your actual use case.

Code:

\documentclass{book}
\usepackage[fleqn]{amsmath}
\usepackage{showframe}

\begin{document}

{%\setlength{\mathindent}{0pt}% <-- brace group to keep these changes local.
\begin{alignat}{3}
    u_\mathrm{L} &= L \cdot \frac{\text{d}i_\mathrm{L}}{\text{d}t} &&\quad(\text{Differential form}) &\label{eq:2_19} \\
   i_\mathrm{L} &= \frac{1}{L} \cdot \int\limits_t u_\mathrm{L} \text{d}t + i_\mathrm{L}(t=0)  &&\quad(\text{Integral form}) \label{eq:2_20}
\end{alignat}
}

\end{document}
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.