Oblicz miejsca zerowe funkcji kwadratowej f i zapisz ją w postaci iloczynowej.
a) f(x)=x^2-4x+4
b) f(x)=-3x^2+9x
c) f(x)=1/2x^2-2
d) f(x)=-2x^2-4x-2
" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
a) f(x)=x^2-4x+4 = (x-2)^2 wynika z e wzoirów skróconego mnożenia
(x-2)^2 = 0
x-2=0
x=2
b) f(x)=-3x^2+9x= 3x(x+3)
3x(x+3) =0
3x=0 i x+3 =0
x = 0 i x=-3
c) f(x)=1/2x^2-2 = 1/2 ( x^2 - 4) = 1/2 (x-2)(x+2)
1/2 (x-2)(x+2)=0
x-2=0 i x+2=0
x= 2 x= -2
d) f(x)=-2x^2-4x-2 = -2x^2 -2x -2x -2 = -2x(x+1) - 2(x+1) = (x+2) (-2x -2)
(x+2) (-2x -2)=0
x+2 =0 i 2x-2=0
x= -2 2x= 2
x=1
a)f(x)=x^2-4x+4
mz: x^2-4x+4=0
Δ=16-16=0
x=4/2
x=2
y=(x-2)^2
b)f(x)=-3x^2+9x
mz: -3x^2+9x=0
x(-3x+9)=0
x=0 ∨ -3x+9=0
x=3
y=-3x(x-3)
c) f(x)=1/2x^2-2
mz:1/2x^2-2=0
1/2x^2=2
x^2=4
x=2 ∨ x=-2
y=1/2(x-2)(x+2)
d) f(x)=-2x^2-4x-2
mz: -2x^2-4x-2=0 /:2
-x^2-2x-1=0
Δ=4-4=0
x=2/-2
x=-1
y=-(x+1)^2