www.varsitytutors.com/hotmath/hotmath_help/topics/vertex-of-a-parabola

y=ax2+bx+c . But the equation for a parabola can also be written in "vertex form": y=a(x−h)2+k. In this equation, the vertex of the parabola is the point (h,k) .

www.purplemath.com/modules/grphquad2.htm

... in the examples). Also, if a is negative, then the parabola is upside-down. ... Find the vertex of y = 3x2 + x – 2 and graph the parabola. To find the vertex, I look ...

www.mathwarehouse.com/geometry/parabola/vertex-of-a-parabola.php

Finding Vertex from Standard Form. The x-coordinate of the vertex can be found by the formula −b2a, and to get the y value of the vertex, just substitute −b2a, ...

www.khanacademy.org/math/algebra/quadratics/quad-standard-form-alg1/v/ex3-completing-the-square

Sal rewrites the equation y=-5x^2-20x+15 in vertex form (by completing the square) in order to identify the vertex of the corresponding parabola.

www.algebralab.org/lessons/lesson.aspx?file=algebra_quad_vertex.xml

The vertex of a parabola is the high point or low point of the graph. The method you use to find the vertex will depend on the form in which the function is given.

www.wikihow.com/Find-the-Vertex-of-a-Quadratic-Equation

The vertex of a quadratic equation or parabola is the highest or lowest point of that equation. It lies on the plane of symmetry of the entire parabola as well; ...

virtualnerd.com/algebra-1/quadratic-equations-functions/graphing/graph-basics/vertex-example

The vertex of a quadratic equation is the minimum or maximum point of the ... problem; skill; vertex; parabola; quadratic function; maximum; minimum; max; min ...