I type $$$A\cdot\left[\begin{array}{cc}\1\\-1\end{array}\right]=\left[\begin{array}{cc}\1\\1\end{array}\right]$$$ but I get $$A\cdot\left[\begin{array}{cc}\1\\-1\end{array}\right]=\left[\begin{array}{cc}\1\\1\end{array}\right]$$
In this array, the font "1" showing in the upper part is much smaller than the one in the lower part. Did I do something wrong? p.s. I am not a Math teacher, so I am sorry for my poor ability to express some ideas about math.
In reply to Alexander Kuo
Re: a strange size happens when using mimetex's array function
by John Forkosh -
Your $$$\begin{array}{cc}\1$$$ should be $$$\begin{array}{cc}1$$$, i.e., $$$\1$$$ indicates a special TeX character, not the number 1. Since standard TeX has no $$$\1$$$ I used it to accommodate someone else's special requirement, and you accidentally stumbled over it. You normally would have gotten a TeX error, but you got my smaller font 1 instead. Try writing $$$A\cdot\left[\begin{array}{r}1\\-1\end{array}\right]=\left[\begin{array}{
r}1\\1\end{array}\right]$$$ and you should see $$A\cdot\left[\begin{array}{r}1\\-1\end{array}\right]=\left[\begin{array}{
r}1\\1\end{array}\right]$$ which is what I think you intended. I also took the liberty of changing your $$${cc}$$$'s to $$${r}$$$'s (since there's just one column, you just need one lcr letter), in case you feel that aligns better.
r}1\\1\end{array}\right]$$$ and you should see $$A\cdot\left[\begin{array}{r}1\\-1\end{array}\right]=\left[\begin{array}{
r}1\\1\end{array}\right]$$ which is what I think you intended. I also took the liberty of changing your $$${cc}$$$'s to $$${r}$$$'s (since there's just one column, you just need one lcr letter), in case you feel that aligns better.