We have been given an incomplete statement. We are supposed to complete the given statement.
Given statement: The vertical line passing through the vertex of a parabola is called the ________.
We know that a parabola is symmetric about axis of symmetry . The line passing through the vertex of parabola divides the parabola into two mirror images.
Therefore, the vertical line passing through the vertex of a parabola is called the the <u>axis of symmetry.</u>
![V(x)= x^{3}- 6x^{2}+8x \\ \\ V(x)=x( x^{2} -6x+8) \\ \\ V(x)=x( x^{2} -2x-4x+8) \\ \\ V(x)=x[x(x-2)-4(x-2)] \\ \\ V(x)=x(x-2)(x-4)](https://tex.z-dn.net/?f=V%28x%29%3D%20x%5E%7B3%7D-%20%206x%5E%7B2%7D%2B8x%20%5C%5C%20%20%5C%5C%20%0AV%28x%29%3Dx%28%20x%5E%7B2%7D%20-6x%2B8%29%20%5C%5C%20%20%5C%5C%20%0AV%28x%29%3Dx%28%20x%5E%7B2%7D%20-2x-4x%2B8%29%20%5C%5C%20%20%5C%5C%20%0AV%28x%29%3Dx%5Bx%28x-2%29-4%28x-2%29%5D%20%5C%5C%20%20%5C%5C%20%0AV%28x%29%3Dx%28x-2%29%28x-4%29%20)