Question

How do you graph the function, label the vertex, axis of symmetry, and x-intercepts. `y = -x^2 + 6x -9`?

Answer 1

Coordinate of vertex:

x = -b/2a = -6/-2 = 3
y = f(3) = -9 + 18 - 9 = 0.

Axis of symmetry: x = -b/2a = 3
`x-"intercepts: "-(x^2 - 6x + 9) = 0 = -(x -3)^2`

There is double root at x = 3.