bonjour,
AF :
(EF)//(BC)
thales
AE/AB = AF/AC=EF/BC
x/2 = AF/3
AF = 3x/2
EF :
AE/EB = EF/BC
x/2 = EF/4
EF = 4x/2 = 2x
P(x) = x+2x+3x/2 = (2x+4x+3x)/2 = 9x/2
P(x) = fonction linéaire
Q(x) = BC+CF+FE+EB
BC = 4
CF = 3-(3x/2)
EF = 2x
EB = 2-x
4+3-(3x/2)+2x+2-x =
9-(3x/2)+x =
9-(3x+2x)/2 =
9-x/2
Q(x) fonction affine