Question

Given ​ f(x)=x^2−2x−5​.

Enter the quadratic function in vertex form.

Answer 1

`f(x) = (x-1)^2-6`

Explanation:

Rewrite the quadratic using the method of completing the square:

`x^2-2x-5=(x^2-2x+1)-1-5=(x-1)^2-6\\f(x) = (x-1)^2-6`

From this form it is immediately clear that the vertex of the parabola is at x=1 and its y-intercept at -6.