Odpowiedzi

2010-03-29T23:34:41+02:00
Mozemy zauwazyc, ze a<0

Xw=-1
Xw= -b/2a
2a=b

P(-2,0) => 4a-2b+c=0
c=0

W(-1,3) => a-b+c=3
-a=3
a=-3

a=-3
b=-6
c=0
1 1 1
2010-03-29T23:45:04+02:00
W(-1;3)=W(-b/2a ; -delta/4a) <=> -b/2a = -1 i -delta/4a=3

-b/2a=-1
-b=-2a
b=2a i P(-2;0)

y=ax^2+bx+c
podstawiamy
0=a(-2)^2-2(2a)+c
-c=4a-4a
c=0

-delta/4a=3
-b^2+4ac/4a=3
-b^2+4ac=12a
-(2a)^2+4*a*0=12a
-4a^2+0=12a
a^2=-3a
a=-3

b=2a
b=-6

a=-3, b=-6, c=0
2 1 2