How do I change the second item (the equation with cases) in the list so - the label (b) is vertically aligned with the lhs of the equation, - the equation in (b) is left aligned with the start of equations in the list, and - there isn't a blank line before the (b) equation begins?
While similar to the question Alignment for Equations with Numbering, Align Number from Enumerate with Question, and Displaying an Equation in a List, I am unable to figure out how to use either minipage
or parbox
to get alignments right.
I include my output, my code, and a (fuzzy) picture of the exercise I am trying to mimic.
\documentclass[11pt]{amsart}
\usepackage{mathtools}
\usepackage{enumitem}
\DeclarePairedDelimiter\floor{\lfloor}{\rfloor} % floor function fences
\begin{document}
Prove that the greatest-integer function, $\floor{x}$, has the properties indicated.
\begin{enumerate}[label=(\alph*)]
\item $\floor{x + n} = \floor{x} + n,$ for every integer $n$.
\item \[
\floor{-x} = \begin{cases}
- \floor{x} & \text{if } x \text{ is an integer}, \\
- \floor{x} -1 & \text{otherwise.}
\end{cases}
\]
\item $\floor{x+y} = \floor{x} + \floor{y} \qquad \text{or} \qquad \floor{x} + \floor{y} +1$.
\item $\floor{2x} = \floor{x} + \floor{x + \frac{1}{2}}$
\item $\floor{3x} = \floor{x} + \floor{x + \frac{1}{3}} + \floor{x + \frac{1}{3}}$
\end{enumerate}
\end{document}