flalign* still maintaining indent - caused by \text{}?

Question

The goal is to align all of the text that spans more than one line with the equal sign. It appears that if I use

\usepackage{amsmath}

in my preamble and then use

align* 

it will align with the equal sign, but has a left indent I don't want (I want my text flush-left). I have found

flalign* 

(again using

\usepackage{amsmath}

in the preamble), but it's not working as the examples I have found work - the text is not flush left. I wonder if it has something to do with \text?

Here is the example I found that WORKS:

\documentclass{article}
\usepackage{showframe}
\usepackage{amsmath}
\begin{document}
\begin{flalign*}
  \cos\theta_1 \cos\theta_2-\sin\theta_1\sin\theta_2 &= \cos(\theta_1 +\theta_2) &\\
  \sin\theta_1 \cos\theta_2 + \cos\theta_1 \sin\theta_2 &= \sin(\theta_1+\theta_2) &
\end{flalign*}
\end{document}

Now, what I really want to be flush-left that ISN'T WORKING:

\documentclass{article}
\usepackage{showframe}
\usepackage{amsmath}
\begin{document}
\begin{flalign*}
  C_C = &\text{ those indices from the set of $k$ where $V$ and $W$ are both observed (i.e.} \\ 
    &\text{ ``completers")}
\end{flalign*}
\end{document}

Again, I can't post an image of my results.

I would like the C_C to be completely flush left. Does it have something to do with \text in my expression, which wasn't used in the example I found that worked?

Answer 1

use

\usepackage[fleqn]{amsmath}
\mathindent=0pt


Answer 2

The working example has ampersands at the end of each line, whereas yours does not. To get the C_C flush left, try this.

\documentclass{article}
\usepackage[a4paper]{geometry}
\usepackage{amsmath}
\begin{document}
\noindent The quick brown fox jumps over the lazy dog.
\begin{flalign*}
C_C = &\text{ those indices from the set of $k$ for which $V$ and $W$ are both observed (i.e.} &\\ 
&\text{``completers'')}&
\end{flalign*}
\end{document}