we have
f(x)=(x-5)^2+4
This is the equation of a vertical parabola open upward written in vertex form
the vertex represent a minimum
y=a(x-h)^2+k
where (h,k) is the vertex
in this problem
(h,k)=(5,4) ------> vertex
In a vertical parabola, the axis of symmetry is equal to the x-coordinate of the vertex
so
axis of symmetry is equal to x=5
using a grahing tool
see the attached image
(please wait a minute)
