# Fixing formatting errors created by long eqnarrays

I'm writing a paper in which I have long eqnarrays, many of them 10 lines or longer. Since TeX seems to not want to page-break these equations, this results in weird formatting, eg pages that have large amounts of whitespace and not much actual text. Is there any way to force TeX to page-break eqnarray equations in a natural way?

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Welcome to TeX.SE. Here is a related question that might be helpful: custom alignment of columns in align environment – Peter Grill Jan 27 '12 at 18:10
Don't use the eqnarray environment; instead, load the amsmath package and use its align environment. To allow page breaks, issue the statement \allowdisplaybreaks. – Mico Jan 27 '12 at 18:19

Avoid eqnarray! Use the amsmath package and its align environment to replace eqnarray. The \allowdisplaybreaks command in the preamble of your document will enable page breaks within equation arrays.
As \allowdisplaybreaks will allow page break after any line in a display environment, its use should be limited to document preparation; for the final version, suitably chosen \displaybreak commands should be used at the spots where page breaks are more convenient. – egreg Jan 27 '12 at 18:25
Just to add, with align, you specify only one & for each line, and it has to be on the left from the equals sign, like `\begin{align} f(x) &= x^2 \\ g(x) &= \sqrt x \end{align} – yo' Jan 27 '12 at 18:31