a) P(-1, 2a) pe grafic => 2*(-1) + a = 2a => -2 = 2a -a => a = -2
b) f(x) = y = 2x -2
pt. y = 0 => 2x -2 =0 => x = 1 => pct. A(1,0)
pt. x = 0 => y = 2*0 - 2 => y = -2 => pct. B(0, -2)
Ducem inaltimea OC perpend. pe AB
AB^2 = OA^2 +OB^2 => AB^2 = 1 + 2^2 = 5 => AB = rad5
T. inaltimii in tr. dreptunghic : inaltimea = c1*c2/ip
OC = OA*OB/AB => OC = 1*2/rad5 = 2*rad5/5
