Vecteurs du plan : première Partie
Savoir placer un point à l'aide d'une relation vectorielle Exercice 1 1
A C → = 1 4 A B → \overrightarrow{AC} =\frac{1}{4} \overrightarrow{AB} A C = 4 1 A B 2
B D → = − 1 2 A B → \overrightarrow{BD} =-\frac{1}{2} \overrightarrow{AB} B D = − 2 1 A B 3
B E → = 2 B A → \overrightarrow{BE} =2\overrightarrow{BA} B E = 2 B A 4
F A → = 1 3 B A → \overrightarrow{FA} =\frac{1}{3} \overrightarrow{BA} F A = 3 1 B A 5
B G → = 3 2 A B → \overrightarrow{BG} =\frac{3}{2} \overrightarrow{AB} B G = 2 3 A B Exercice 2 1
A M → = 1 2 A B → + A C → \overrightarrow{AM} =\frac{1}{2} \overrightarrow{AB} +\overrightarrow{AC} A M = 2 1 A B + A C 2
B N → = − 1 4 A B → − B C → \overrightarrow{BN} =-\frac{1}{4} \overrightarrow{AB} -\overrightarrow{BC} B N = − 4 1 A B − B C 3
C P → = C A → + A B → \overrightarrow{CP} =\overrightarrow{CA} +\overrightarrow{AB} C P = C A + A B 4
A Q → = 2 A C → − B A → \overrightarrow{AQ} =2\overrightarrow{AC} -\overrightarrow{BA} A Q = 2 A C − B A Exercice 3 1
A M → = 1 2 A C → + A D → \overrightarrow{AM} =\frac{1}{2} \overrightarrow{AC} +\overrightarrow{AD} A M = 2 1 A C + A D 2
B N → = 1 2 D C → − D B → \overrightarrow{BN} =\frac{1}{2} \overrightarrow{DC} -\overrightarrow{DB} B N = 2 1 D C − D B 3
D P → = 1 3 D B → + A D → \overrightarrow{DP} =\frac{1}{3} \overrightarrow{DB} +\overrightarrow{AD} D P = 3 1 D B + A D 4
C Q → = − 1 2 D A → + C A → − 3 2 A D → \overrightarrow{CQ} =-\frac{1}{2} \overrightarrow{DA} +\overrightarrow{CA}-\frac{3}{2}\overrightarrow{AD} C Q = − 2 1 D A + C A − 2 3 A D 
