Răspuns:
a)A(0,1)∈Gf
f(0)=1
f(0)=1-2×0
1-2×0=1
1-0=1
1=1=>A(0,1)
b)AB=2√5
OA=1
OB=?
AB²=OA²+OB²
(2√5)²=1²+OB²
20=1+OB²
OB=√19=> b(0,√19)
la b) nu sunt sigur
