Left align problems

Question

I have no idea how to ask a question in here as I tried pasting my latex document in (it is only short) to demonstrate my issue but it does not look like anything else here and I don't want to piss anyone off.

Advice on that welcome.

Either way, I have a series of equations that need to be aligned. The first one is too long to fit on a single line so I want to put it as far to the left as possible. I have tried {flalign*} but it has no effect.

There is one question here ( How to move the whole block of {align*} to the left? ) that I have pasted into a new document and it works.

However when I paste my equations into this document in place of what is between \begin{flalign*} and \end{flalign*} and nothing changes.

I have inserted & at he end of the line both with and without \\[1.5ex]

Nothing seems to work.

Once I get the align issue sorted I'll also need to think about splitting right aligning the latter part of the first equation.

Any ideas?

Thanks and apologies in advance.

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{setspace}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage{textcomp}
\usepackage{mathtools}
\usepackage{leftidx}
\usepackage[none]{hyphenat}
\usepackage{float}
\usepackage{nicefrac}
\raggedright
\doublespacing
\pagestyle{myheadings}
\markright{Jesmond Jester\hfill MST124 TMA 04\hfill}
\author{JesmondJester}
\title{TMA 04}
\begin{document}
\setlength{\abovedisplayskip}{0pt}
\setlength{\belowdisplayskip}{0pt}
\Large
\maketitle
\newcommand{\degrees}{\ensuremath{^\circ}} 


\begin{align*}% this is centered
a &=b
\end{align*}
%
\begin{flalign*}
a&=b&\\% Need this tailing alignment char to get all the way left
\end{flalign*}


\begin{flalign*}
&=1+\left(-\tfrac{3}{5}\right)x+\frac{\left(-\frac{3}{5}\right)\left(-\frac{8}{5}\right)}{2!}x^2+\frac{\left(-\frac{3}{5}\right)\left(-\frac{8}{5}\right)\left(-\frac{13}{5}\right)}{3!}x^3+\\ \frac{\left(-\frac{3}{5}\right)\left(-\frac{8}{5}\right)\left(-\frac{13}{5}\right)\left(-\frac{18}{5}\right)}{4!}x^4+...&\\[1.5ex]
&=1-\frac{3}{5}x+\frac{3\times8}{5^2\times2!}x^2-\frac{3\times8\times13}{5^3\times3!}x^3+\frac{3\times8\times13\times18}{5^4\times4!}x^4-&\\[1.5ex]
&=1-\frac{3}{5}x+\frac{12}{25}x^2-\frac{52}{125}x^3+\frac{234}{625}x^4-...&\\
\end{flalign*}


\end{document}

Answer 1

Tough, as many big formulas. Shoving everything to the left doesn't seem to be the best solution, but you can do it, just remembering to add some &.

I also propose a centered solution with a dirty trick for getting the trailing dots aligned to each other in the longer lines.

\documentclass{article}
\usepackage{amsmath,mathtools}

% this is just for the last example; the name can be changed, of course
\makeatletter
\newcommand\jester{%
  \ifmeasuring@
    0pt
  \else
    \dimexpr\ifcase\expandafter 2\maxcolumn@widths\fi-1.5\multlinegap\relax
  \fi
}
\makeatother

\begin{document}

This is overfull by 31pt
\begin{flalign*}
&=
  1+
  (-\tfrac{3}{5})x+
  \frac{(-\frac{3}{5})(-\frac{8}{5})}{2!}x^2+
  \frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})}{3!}x^3+
  \frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})(-\frac{18}{5})}{4!}x^4+
  \dotsb&\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{3\times8}{5^2\times2!}x^2-
  \frac{3\times8\times13}{5^3\times3!}x^3+
  \frac{3\times8\times13\times18}{5^4\times4!}x^4-\dotsb&\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{12}{25}x^2-
  \frac{52}{125}x^3+
  \frac{234}{625}x^4-\dotsb&
\end{flalign*}

This one isn't, but the result is really bad
\begin{flalign*}
&=
  1+
  (-\tfrac{3}{5})x+
  \frac{(-\frac{3}{5})(-\frac{8}{5})}{2!}x^2+
  \frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})}{3!}x^3\\
&\qquad\qquad
  +\frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})(-\frac{18}{5})}{4!}x^4+
  \dotsb&\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{3\times8}{5^2\times2!}x^2-
  \frac{3\times8\times13}{5^3\times3!}x^3+
  \frac{3\times8\times13\times18}{5^4\times4!}x^4-\dotsb&\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{12}{25}x^2-
  \frac{52}{125}x^3+
  \frac{234}{625}x^4-\dotsb&
\end{flalign*}

Here's a different implementation
\begin{align*}
f(x)
&=\begin{multlined}[t][\jester]
  1+
  (-\tfrac{3}{5})x+
  \frac{(-\frac{3}{5})(-\frac{8}{5})}{2!}x^2+
  \frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})}{3!}x^3\\
    +\frac{(-\frac{3}{5})(-\frac{8}{5})(-\frac{13}{5})(-\frac{18}{5})}{4!}x^4+
  \dotsb
  \end{multlined}\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{3\times8}{5^2\times2!}x^2-
  \frac{3\times8\times13}{5^3\times3!}x^3+
  \frac{3\times8\times13\times18}{5^4\times4!}x^4-\dotsb\\[1.5ex]
&=
  1-
  \frac{3}{5}x+
  \frac{12}{25}x^2-
  \frac{52}{125}x^3+
  \frac{234}{625}x^4-\dotsb
\end{align*}

\end{document}