[PS] Add more notes

semester4/ps/ps-jh/parts/03_expected-value/05_variance.tex

@@ -1,6 +1,4 @@
 \subsection{Varianz}
-$\E[\cX^2] = \sum_{x \in W} x^2 \cdot p_\cX(x)$ ($\cX$ diskret)
-
 \shortdefinition $\cX$ mit $\E[\cX^2] < \8$, $\V[\cX] = \E[(\cX - \E[\cX])^2]$
 
 \shortdefinition[Standardabweichung] $\sigma(\cX) = \sqrt{\V[\cX]}$