f(x) = ax² +bx+c a≠0
tg axei Ox conditie Δ=0
Δ= b²-4ac b² -4ac=0 si x virf = -b/2a = -4 -b= -8a
b=8a
64a² =4ac 64a² -4ac=0 4a ( 16a - c)=0 a=0 fals
16a-c=0 c=16a
b²= 4ac
A ( -2 , -4) f(- 2 ) =-4
4a-2b +c=- 4
4a -16a +16a=-4 a=-1 b=-8 c=-16
f(x) =- x² -8x -16
