Réponse :
1) P(x) = 3x²-x+2=0
b²-4ac=(-1)²-4(3*2) = 1-24=-23
Δ<0 ne se resous pas ds R
2) -5x²-9x+2=
b²-4ac =(-9)²-4(-5*2)=81-4(-10) = 81+40=121
Δ>0 2solutions
(-b-√Δ)/2a= (9-11)/-10=-2/-10=1/5
(-b+√Δ)/2a=(9+11)/-10 = -2
x1=1/5
x2=-2
facto =-5(x-1/5)(x-2)
3) P(x) = x²/3 -2x +3
b²-4ac = (-2)²-4(1/3*3) = (-2)²-4(1) = 0
Δ =0
-b/2a=6/2=3
facto : 1/3(x-3)²
4) P(x) = 3x²-4x+1
b²-4ac = (-4)²-4(3*1) = 16-12=4
Δ>0 2solutions
(-b-√Δ)/2a=(4-2)/6 = 2/6=1/3
(-b+√Δ)/2a =(4+2)/6 = 6/6=1
x1=1/3
x2=1
facto : 3(x-1/3)(x-1)
Explications étape par étape :
