Chapitre sur les vecteurs (seconde) Bonjour a tous pouvez vous m'aider. Avant de placer les points il faut faire certains calculs comme indiqué. Ce sue j'ai mar

1) vect MA= -1/2 vect MB
vectMB= vectMA +vect AB

vect MA = -1/2 (vectMA + vect AB)
vect MA = -1/2 vect MA - 1/2 vect AB
3/2 vect MA = -1/2 vect AB
vect MA = -1/3 vect AB ⇒ VECT AM = 1/3 vect AB

2) vect SB = 2 vect SC

VECT SC = vect SB+ VECT BC

 vect SB  = 2  ( vect SB+ VECT BC)

vect SB - 2vect  SB = 2 vect BC

-vect SB = 2 vect BC

vect BS = -2 vect BC

3) vect BT =-1/4 vect DT 

Vect DT = vect DB + vect BT

vect BT =-1/4  (vect DB + vect BT)


vect BT = -1/4 vect DB -1/4 vect BT

5/4 vect BT = -1/4vect DB

vect BT = 1/5 vect BD



3 EME PARTIE

vect AU = vect AB +vect AC -VECT BC

vect AU = vect AB + vect AC + VECT CB

vect AU = vect AB + Vect AB

vect AU = 2 vect AB



vect AV = vect AC -vectAD+ vect QD
VECT AV = vect AC + VECT DA + vect QD

vect AV = vect DC+ vect QD

vect AV = vect QC


le plus long est d'écrire vect