Confused about how to insert fractions into matrices

[Eclair_de_XII]

TL;DR

I keep trying to type in the code in the body of this message out, but the console returns this error message:

"! Missing \endgroup inserted.
<inserted text>
\endgroup
l.115 \frac
{\partial f^1}{\partial u} & \frac{\partial f^1}{\partial v} \\"

[CODE highlight="10"]$$c'\begin{pmatrix}u \\ v \end{pmatrix}=\begin{pmatrix}\frac{\partial f^1}{\partial u} & \frac{\partial f^1}{\partial v} \\\frac{\partial f^2}{\partial u} & \frac{\partial f^2}{\partial v}\end{pmatrix}

$$[/CODE]

There is a problem with the first line of the matrix, but I am not too sure what it is.

 

[Mark44]

I don't see what the problem is. Here is almost identical LaTeX code, with the only differences being I used inline delimiters rather than the standalone $ delimiters, and I didn't include what you have at the start of your first line -- i.e., c'\begin{…}. What's the purpose of c'? I thought at first it might be a comment, but that doesn't seem to be the case.

$\begin{pmatrix}u \\ v \end{pmatrix}=\begin{pmatrix} \frac{\partial f^1}{\partial u} & \frac{\partial f^1}{\partial v} \\ \frac{\partial f^2}{\partial u} & \frac{\partial f^2}{\partial v} \end{pmatrix}$

 

[Eclair_de_XII]

It's the derivative of a function mapping $\mathbb{R}^2$ to $\mathbb{R}^2$.

 

[Orodruin]

Remove the blank lines, they are not allowed in math mode. If you really want to create space in your code like this, use lines with a single comment (%).

 

[Eclair_de_XII]

Okay, thanks for the tip.