Question

Rezolva-ti exercițiul!​

Answer 1

Răspuns:

f(x) =-3x²+10x+8

Explicație pas cu pas:

f(5/3)=0

a<0 pt ca avem maxim

-b/2a=2/3

-Δ/4a=49/3

convine forma canonica

f(x) =a (x+b/2a)²-Δ/4a

f(x) =a(x+2/3)² +49/3

f(5/3) =0

a(7/3)²+49/3=0

a*49/9=-49/3

a/9=1/3

a/3=-1

a=-3

a=-3

-b/2a=5/3

-b/-6=5/3

b/6=5/3

b/2=5........b=10

-Δ/4a=49/3

-(b²-4ac)/(-12)=49/3

(b²-4ac)/12=49/3

(b²-4ac)/4=49

b²-4ac=196

100-4(-3)*c=196

12c=96

c=8

f(x) =-3x²+10x+8

a iesit frmos la c, nu mai verific toata povestea...dar -b/2a se vede imediat