TeX Quellcode:
\vec{PQ}=\begin{pmatrix}x_q\cr y_q\end{pmatrix}-\begin{pmatrix}x_p\cr y_p\end{pmatrix}=\begin{pmatrix}x_q-x_p\cr y_q-y_p\end{pmatrix}=\begin{pmatrix}x\cr y\end{pmatrix}