The graph that has an axis of symmetry at x = 3 is f(x) = x2 – 6x – 1.
You can find the axis of symmetry by using the equation to find the x value of the vertex. The x value of the vertex is always the axis of symmetry in a quadratic graph. The equation is below.
x = -b/2a
In this equation, a is the coefficient of x^2 and b is the coefficient of x. If we use the numbers from the last equation in your list, a = 1, b = -6.
x = -b/2a
x = -(-6)/2(1)
x = 6/2
x = 3
