\(\overrightarrow{XY}\) = \(\overrightarrow{OY}\) - \(\overrightarrow{OX}\)
→
2 \(\overrightarrow{PM}\) = 2 • (\(\overrightarrow{OM}\) - \(\overrightarrow{OP}\) ) = 2 • ( 1/2 • (\(\overrightarrow{OA}\) + \(\overrightarrow{OB}\) ) - \(\overrightarrow{OP}\))
= \(\overrightarrow{OA}\) + \(\overrightarrow{OB}\) - 2 \(\overrightarrow{OP}\) = \(\overrightarrow{OA}\) - \(\overrightarrow{OP}\) + \(\overrightarrow{OB}\) - \(\overrightarrow{OP}\) = \(\overrightarrow{PA}\) + \(\overrightarrow{PB}\)
Gruß Wolfgang