Question

How do you graph the function, label the vertex, axis of symmetry, and x-intercepts. `y=-x^2+6x-4`?

Answer 1

x of vertex: `x = (-b/2a) = -6/-2 = 3`

y of vertex: `y = f(3) = -9 + 18 - 4 = 5`

Vertex form: `f(x) = -(x -3)^2 + 5.`

Check by developing: `f(x) = -(x^2 - 6x + 4) + 5 = -x^2 + 6x - 4.` OK