Question

f(x)=x²-6x+9. a=___,b=___,c=___


g(x)=x²-4x. a=____,b=____,c=____


h(x)=x²+2
a=___,b=____,c=____



m(x)=(x-3)²-4

a=____,b=____,c=____

Answer 1

a=1 b=-6 c=9
a=1 b=-4 c=0
a=1 b=0 c=2
a=-3 b=0 c=-4

x²+2x-8=9
a=1 b=2 c=-8
∆=b²-4.a.c
∆=2²-4.1.(-8)
∆=4+32
∆=36
x=-b±√∆/2.a
x=-2±√36/2.1
x=-2±6/2
x'=-2+6/2=4/2=2
x"=-2-6/2=-8/2=-4
S{(-4,2)}

x²+10x+25=0
a=1 b=10 c=25
∆=b²-4.a.c
∆=10²-4.1.25
∆=100-100
∆=0
x=-b±√∆/2.a
x=-10±√0/2.1
x=-10±0/2
x=-10/2
x=-5
S={(-5)}

x²+4x+5=0
a=1 b=4 c=5
∆=b²-4.a.c
∆=4²-4.1.5
∆=16-20
∆=-4
S=0 ou S={( )}