Answer:
(1,-9)
Step-by-step explanation:
[tex]f(x)=x^2-2x-8 \\\\f(x)=(x^2-2x+1)-1-8 \\\\f(x)=(x-1)^2-9[/tex]
Since the form of a parabola in vertex form is [tex]a(x-h)^2+k[/tex], where h is the x coordinate of the vertex and k is the y coordinate, the vertex of this parabola is at (1,-9). Hope this helps!