Question

whats the vertex of f(x)=x^2-2x-8

Answer 1

change it to the completed square form...
can u?

Answer 2

no

Answer 3

the first coordinate of the vertex is alway \(-\frac{b}{2a}\)
in your case it is \(-\frac{-2}{2\times 1}=1\)
the second coordinate of the vertex is what you get when you replace \(x\) by that number

Answer 4

1^2-2(1)-8=...

Answer 5

the completed square form is a(x-h)^2+k

Answer 6

try to take it to that form