What quadratic function does the graph represent?

Answer:
[tex]f(x)=-\frac{1}{3}(x-2)^2+4[/tex],
Step-by-step explanation:
The function of the graph can be written in the vertex form as
[tex]f(x)=a(x-h)^2+k[/tex], where V(h,k)=V(2,4) is the vertex of the quadratic function.
We substitute the value to obtain;
[tex]f(x)=a(x-2)^2+4[/tex],
The point (5,1) lies on the graph so we use it to determine the value of a.
[tex]1=a(5-2)^2+4[/tex],
[tex]1-4=a(3)^2[/tex],
[tex]-3=9a[/tex],
[tex]a=-\frac{1}{3}[/tex]
The required equation is
[tex]f(x)=-\frac{1}{3}(x-2)^2+4[/tex],