Hi I was struggling to maximise this function wrt to $x$. $B$ is a weight matrix.
$\\y_{i} = \binom{y_{1i}}{y_{2i}}.$
Function: $\left [\frac{1}{n}\sum_{i} y_{i} - \binom{1}{2}x \right ]' B \left [\frac{1}{n}\sum_{i} y_{i} - \binom{1}{2}x \right ]$,
First Derivative Answer:$\ (1,2) B \left [\frac{1}{n}\sum_{i} y_{i} - \binom{1}{2}x \right ] = 0$
I tried using this rule:
