bonjour
formule de la forme canonique :
a (x- α)² +β
α = -b/2a
β =f(α) =f(-b/2a)
1)
x²+3x-10
a=1
α=-b/2a = -3/2
β=f(-3/2)
=(-3/2) ²+3 × (-3/2)-10 =-49/4
f(x) =(x +3/2 )² - 49/4
2)
x²+7x+11
m^me méthode
a=1
α= -7/2
β=f(-7/2)=-5/4
f(x) =(x+7/2)²-5/4
3)
-3x²+10x+8
a=-3
α=-10/2×-3= -10/-6= 5/3
β=f(5/3)=49/3
f(x) = -3(x-5/3)²-49/3
4)
30x²+19x-5
a= 30
α= -19/2× 30 = -19/60
β=f(-19/60)=30×(-19/60)²+19×(-19/60) -5
= -961/120
f(x)= 30(x+19/60)²-961/120
