\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
Pour \(\|\Vect{u}\|=3\), et \(\Vect{u}\cdot \Vect{v} =1\), calculer :
\((\Vect{u}+\Vect{v}) \cdot (2\Vect{u}) =\)