The extreme point is called a vertex.
focus
All of the points on a parabola define a parabola. However, the vertex is the point in which the y value is only used for one point on the parabola.
"From the geometric point of view, the given point is the focus of the parabola and the given line is its directrix. It can be shown that the line of symmetry of the parabola is the line perpendicular to the directrix through the focus. The vertex of the parabola is the point of the parabola that is closest to both the focus and directrix."-http://www.personal.kent.edu/~rmuhamma/Algorithms/MyAlgorithms/parabola.htm"A line perpendicular to the axis of symmetry used in the definition of a parabola. A parabola is defined as follows: For a given point, called the focus, and a given line not through the focus, called the directrix, a parabola is the locus, or set of points, such that the distance to the focus equals the distance to the directrix."-http://www.mathwords.com/d/directrix_parabola.htm
Vertex
The highest or lowest point of the parabola, it is the point that is closest to the focus. The extreme point lies on the axis of symmetry
The extreme point is called a vertex.
The vertex -- the closest point on the parabola to the directrix.
This extreme point on the parabola is called the vertex. In math. a parabola is a U-shaped curve with a directrix, which is a fixed straight line.
It is the vertex of the parabola.
The extreme point is called a vertex.
The vertex, or maximum, or minimum.
focus
It is either a maximum or minimum value depending on its downwards shape or its upwards shape
A parabola is NOT a point, it is the whole curve.
focus directrix
All of the points on a parabola define a parabola. However, the vertex is the point in which the y value is only used for one point on the parabola.