Vertex (algebraic)

My Definition

Key Characteristics

The following are true of a vertex (algebraic):

- The vertex can be a minimum or maximum point.
- For parabolas opening up or down, the
*x*-value of the vertex is equidistant from the*x*values of the*x*-intercepts. - For parabolas opening up or down, the
*y*-value of the vertex is equidistant from the*y*value of the focus and the closest point on the directrix. - For parabolas opening up or down, the
*x*-value of the vertex is same as the*x*-value of all the points on the axis of symmetry. - The
*x*-value can be found using the formula*h*=-for a parabola with the equation*b*2*a**y*=*ax*^{2}+*bx*+*c*. - The
*y*-value can be found by using the*x*-value into the equation,*y*=*ax*^{2}+*bx*+*c*, and simplifying. - Similar statements can be made for parabolas opening to the left and right.

Example

Non-example

TEKS: A(6)(B), A(7)(A)