# How to align the implies sign within the enumerate environment

For example, how to align the implies sign here

\begin{enumerate}
\item $\frac{\mathrm{d}}{\mathrm{dx}} \left(\frac{x^{n+1}} {n+1}\right)=x^n,n\neq 1\qquad \Rightarrow\int x^n.\mathrm{dx}=\frac{x^{n+1}}{n+1} +\mathrm{C},n\neq 1$
\item $\frac{\mathrm{d}}{\mathrm{dx}} \left(\log_e x\right)=\frac{1} {x}\qquad \Rightarrow\int\frac{1}{x} .\mathrm{dx}=\log_e x+\mathrm{C}$
\end{enumerate}


I am unable to use \begin{align*} here because can't use align environment in enumerate environment. So how do I the align the implies sign in the above code?

• First of all why are you using a list here? I see no reason to do so. Additionally, please provide a full minimal example instead of a sniplet. That makes testing your code much easier for us, plus det can see what kind of class and preamble you are using as that affects our answers. – daleif Feb 11 '20 at 17:14
• Welcome to TeX SX! You can use align after \item, but you'll have a (possibly unwanted) vertical space. If you don't want it, use the aligned environment. – Bernard Feb 11 '20 at 17:16

Set each of the left-hand sides in a box of largest width. This process is automated via eqparbox's \eqmakebox[<tag>][<align>]{<stuff>}; all boxes with the same <tag> are fit inside a box of greatest width within that <tag>, with the possibility to <align> the content as well:

\documentclass{article}

\usepackage{eqparbox}

\begin{document}

\begin{enumerate}
\item \eqmakebox[largest]{$\frac{\mathrm{d}}{\mathrm{d}x} \Bigl( \frac{x^{n + 1}}{n + 1} \Bigr) = x^n, n \neq 1 \qquad$}%
$\Rightarrow \int x^n\,\mathrm{d}x = \frac{x^{n + 1}}{n + 1} + \mathrm{C}, n \neq 1$
\item \eqmakebox[largest][l]{$\frac{\mathrm{d}}{\mathrm{d}x} \bigl( \log_e x \bigr) = \frac{1}{x}$}%
$\Rightarrow \int \frac{1}{x}\,\mathrm{d}x = \log_e x + \mathrm{C}$
\end{enumerate}

\end{document}


Another solution using a canonical code (aligned + \usepackage{derivative} to obtain directly the d in math-roman mode).

\documentclass[12pt]{article}
\usepackage{mathtools}
\usepackage{derivative}
\begin{document}
\begin{enumerate}
\item
\begin{aligned}[t] \odv{}{x}\biggl(\frac{x^{n + 1}}{n + 1} \biggr) &= x^{n}, n \neq 1 &&&&\Rightarrow \int x^{n} \mathrm{d}x = \frac{x^{n + 1}}{n + 1} + \mathrm{C},\,n \neq 1 \end{aligned}
\item
\begin{aligned}[t] \odv{}{x}\bigl( \ln x \bigr)& =\frac{1}{x} &&&&&&&&&&\,\qquad \Rightarrow \int \frac{1}{x}\,\mathrm{d}x = \ln x + \mathrm{C} \end{aligned}
\end{enumerate}
\end{document}


Like this?

Assuming, that enumerate is not intended for equation numbers, you can use flaign math environment from the amsmath package:

\documentclass{article}
\usepackage{amsmath}

\begin{document}
\begin{flalign*}
1.  &&   \frac{\mathrm{d}}{\mathrm{dx}} \left(\frac{x^{n+1}}{n+1}\right) = x^n,n\neq 1
&   \Rightarrow \int x^n \mathrm{dx} = \frac{x^{n+1}}{n+1} +\mathrm{C},n\neq 1
&&   \\
2.  &&   \frac{\mathrm{d}}{\mathrm{dx}} \left(\log_e x\right)=\frac{1}{x}
&  \Rightarrow \int\frac{1}{x} \mathrm{dx} = \log_e x+\mathrm{C}
&&   \\
\end{flalign*}
\end{document}