Finding y-intercept, equation of the axis of symmetry, and x-coordinate of the vertex of a quadratic function

For the function  f(x) = x² - 6x + 8,
Find the y-intercept, the equation of the axis of symmetry, and the x-coordinate of the vertex.

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f(x) = x² - 6x + 8

The y-intercept is 8.

The function is in the form f(x) = ax² + bx + c
a = 1, b = -6, and c = 8

-b
---- = x  {equation of axis of symmetry}
2a

-(-6)
------- = x   {substituted given information into equation}
 2(1)

6
--- = x   {simplified}
2

x = 3   {divided}

The equation of the axis of symmetry is x = 3.

The vertex is located on the axis of symmetry, therefore
the x-coordinate of the vertex is 3.

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