Equation goes outside the boundary with eqnarray environment!

Question

I am trying to use the following. Unfortunately, the last line goes outside the page. How to fix this or is there another way to write the same?

\documentclass{article}
\usepackage{eqnarray,amsmath}
\begin{document}

\begin{eqnarray*}\label{alphaf}
\alpha+M(d(fx_n,fz_n))&\leq&\alpha+\alpha(fx_n,fz_m)M(d(fx_n,fz_k))\\&\leq& M(M_{f,h}(fx_n,fz))\\&=&M(x,y)\bigg(max\left\{d(fx_n,fz),d(fx_n,fx_n),d(fz,fz),\frac{d(fx_n,fz)+d(fz_b,fx_n)}{h}\right\}\bigg)
\end{eqnarray*}
\end{document}

what does the vertical rule indicate? it's neither the page boundary nor the boundary of the text block. (i assumed the latter in proposing an answer, but now that i've had a chance to test, it clearly doesn't work, and will be deleted.) — barbara beeton, Oct 03 '16 at 17:09

score 7 · Accepted Answer · edited Apr 13 '17 at 12:35

You have to break the too-long equation manually. Here's a way to do so it seems natural, using some spacing adjustment via \phantom:

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\begin{align*}
  \alpha + M(d(fx_n,fz_n)) &\leq \alpha + \alpha(fx_n,fz_m) M(d(fx_n,fz_k)) \\
                           &\leq M(M_{f,h}(fx_n,fz)) \\
                           &= M(x,y) \max \bigl\{ d(fx_n,fz),d(fx_n,fx_n), \\
                           &\phantom{{}={} M(x,y) \max \bigl\{}d(fz,fz),\tfrac{d(fx_n,fz)+d(fz_b,fx_n)}{h} \bigr\}
\end{align*}

\end{document}

Please avoiding using eqnarray.

Mico · Answer 2 · 2016-10-02T06:36:01.580

Another align*-based solution. It differs from @Werner's solution in the way the final row's indentation is achieved and in the treatment of the fractional expression in the final row.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*}
\alpha+M(d(fx_n,fz_n))
&\leq\alpha+\alpha(fx_n,fz_m)M(d(fx_n,fz_k))\\
&\leq M(M_{f,h}(fx_n,fz))\\
&= M(x,y)\max\bigl\{ d(fx_n,fz),d(fx_n,fx_n),\\
&\qquad\qquad d(fz,fz),\tfrac{1}{h}\bigl[d(fx_n,fz)+d(fz_b,fx_n)\bigr] \bigr\}
\end{align*}
\end{document}

score 4 · Answer 3 · answered Oct 02 '16 at 10:44

I'll add three other variants:

\documentclass{article}
\usepackage[showframe]{geometry}%
 \usepackage{mathtools, nccmath}

\begin{document}

\begin{align*}
  \alpha+M(d(fx_n,fz_n))
    & \leq\alpha+α(fx_n,fz_m)M(d(fx_n,fz_k)) \\
    & \leq M(M_{f,h}(fx_n,fz)) \\
    & =\!\begin{multlined}[t] M(x,y)\max\bigl\{ d(fx_n,fz),d(fx_n,fx_n), d(fz,fz), \\[0.5ex]
  \mfrac{1}{h}\bigl[d(fx_n,fz)+d(fz_b,fx_n)\bigr] \bigr\}
  \end{multlined}
\end{align*}

\begin{align*}
  \alpha+M(d(fx_n,fz_n))
  &\leq\alpha+α(fx_n,fz_m)M(d(fx_n,fz_k))\\
  &\leq M(M_{f,h}(fx_n,fz))\\
    & =\!\begin{aligned}[t] M(x,y)\max\bigl\{ d(fx_n,fz),d(fx_n,fx_n), d(fz,fz) & , \\
  \mfrac{1}{h}\bigl[d(fx_n,fz)+d(fz_b,fx_n) & \bigr] \bigr\}
  \end{aligned}
\end{align*}

\begin{align*}
  \alpha+M(d(fx_n,fz_n))
    & \leq\alpha+α(fx_n,fz_m)M(d(fx_n,fz_k)) \\
    & \leq M(M_{f,h}(fx_n,fz)) \\
    & =\! M(x,y)\max \!\begin{Bmatrix*}[r]d(fx_n,fz),d(fx_n,fx_n), d(fz,fz), \\[0.5ex]
  \mfrac{1}{h}\bigl[d(fx_n,fz)+d(fz_b,fx_n)\bigr]
  \end{Bmatrix*}
\end{align*}

\end{document}

score 3 · Answer 4 · answered Oct 03 '16 at 10:10

You can use multlined from mathtools.

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

\usepackage{showframe} % just for this example

\begin{document}

\begin{align*}
\alpha + M(d(fx_n,fz_n))
  &\leq \alpha + \alpha(fx_n,fz_m) M(d(fx_n,fz_k)) \\
  &\leq M(M_{f,h}(fx_n,fz)) \\
  &= \!\begin{multlined}[t]
     M(x,y) \max \biggl\{ d(fx_n,fz),d(fx_n,fx_n),
     \qquad\qquad % make the top a bit wider
     \\
     d(fz,fz),\frac{d(fx_n,fz)+d(fz_b,fx_n)}{h} \biggr\}
     \end{multlined}
\end{align*}

\end{document}

Note: showframe is only used to show the text block margins

Equation goes outside the boundary with eqnarray environment!

4 Answers4