y=ax²+bx+c
Here, a=1, b=-6 c=5
The axis of symmetry is x=-b/2a
x= -(-6)/2(1)
x=6/2
x=3
Now the y term of the axis of symmetry just means you have to plug in x=3 in to your quadratic equation for find the y term of your vertex.
y=(3)²-6(3)+5
y=9-18+5
y=-9+5
y=-3
So the vertex is (-b/2a,f(-b/2a))
So it will be (3,-3)
