How do you graph the quadratic function and identify the vertex and axis of symmetry for y=x^2-2x-1?

1 Answer
Feb 12, 2018

Vertex: (1,-2)
Axis of Symmetry: x=1

Explanation:

You first convert to vertex form:

y=a(x-h)^2+k with (h,k) being the vertex. To get to this, you have to complete the square.

y=(x-2x+1^2-1^2)-1

y=(x-1)^2-2

Since the vertex is (h,k), then the vertex here is (1,-2).

The axis of symmetry is just the x-coordinate of the vertex or x=-b/(2a) in y=ax^2+bx+c:

x=1 is the axis of symmetry.