Question

Aflati minimul expresiei
x₂+4x+5

Answer 1

x²+4x+5= 0  pt ca expresia sa fie minima o egalam cu 0

a=1
b=4
c=5
Δ= -16 -4*5*1= -16-20=-36

x1,x2= 16 +/- (-√36)/2=  16 +/- (-6)/2

x1=16+(-6)/2=  10/2=5
x2=16 -(-6)/2= 22/2=11

x²+4x+5= (x-5)(x-11)

(x-5)(x-11)=0
x-5=0   x-11=0
x=5      x=11  ⇒solutia minima=5