Forcing non-italic captions Up: Miscellaneous Latex syntax Previous: Defining and using colors How do I insert the symbol for 'n choose x'? Use the Latex command {n \choose x} in math mode to insert the symbol.Or, in Lyx, use \binom(n,x).

To fix this, simply add a pair of braces around the whole binomial coefficient, i.e. {N\choose k} (The braces around N and k are not needed.). However, as you're using LaTeX, it is better to use \binom from amsmath, i.e. \binom{N}{k}.

Creating your first LaTeX document; Choosing a LaTeX Compiler; Paragraphs and new lines; Bold, italics and underlining; Lists; Errors Mathematics. Mathematical expressions; Subscripts and superscripts; Brackets and Parentheses; Fractions and Binomials; Aligning Equations; Operators; Spacing in math mode; Integrals, sums and limits; Display style in math mode.

The amsmath package provides a handful of options for displaying equations. You can choose the layout that better suits your document, even if the equations are really long, or if you have to include several equations in the same line.