merged Martins branch with mine

K2A2 did not have my solution. i added it again.
mergeconflict with the pdf files for K2 and K3. just compiled them again
with the new tasks tex files.

documents/Numerik/Klausur3/Aufgabe1.tex

@@ -1,5 +1,8 @@
 \section*{Aufgabe 1}
 \subsection*{Teilaufgabe a)}
+\paragraph{Gegeben:} Sei $A \in \mathbb{R}^{3 \times 3}$.
+\paragraph{Gesucht:} Cholesky-Zerlegung $A = L \cdot L^T$
+\paragraph{Rechnung:}
 
 Erste Spalte:
 \begin{align}