Is there a symbol for the inverse? I have been using X^{-1} for my matrix inversions, but this results in the -1 being rather large and taking up almost as much room as another symbol. Is there a built in symbol or trick I should be using?
[Tex/LaTex] Matrix Inverse symbol
formattingmath-mode
Related Solutions
An index can be a scalar, or a vector in its own right: compare $\vec{x}_r$ with $\vec{x}_{\vec{r}}$ - these are different mathematical entities! The dimensions of the index may not coincide with the dimensions of the indexed object.
Therefore as a general rule your variant 1 should be preferred: it shows that the quantity is a vector or a matrix with a scalar index (or vector index if appropriate).
Of course some journals and publishers introduce their own "house styles" which may have different recommendations. Sadly enough, sometimes these "house styles" are written without input from the mathematicians, so I can envision a style that requires (mathematically unsound) variant 2.
\documentclass[]{article}
\usepackage{mathtools}
\begin{document}
\[
\left(
\begin{array}{ccccc}
1 \\
& 1 & & \text{\huge0}\\
& & 1 \\
& \text{\huge0} & & 1 \\
& & & & 1
\end{array}
\right)
\]
\end{document}
or \makebox(0,0){\text{\huge0}} if you want to have the same line spacing.
Best Answer
If you just want to reduce the size of the
-1term, you could create your own macro called, say,\inv{...}, along the lines of the code below. The screenshot shows the look of both\inv{X}andX^{-1}. (The vertical offset of1.15exis chosen so that the tops of the1symbols are at very nearly the same height using either\inv{...}orX^{-1}. Feel free to adjust the offset to suit your preferences.)