STEP 1: Recall what is a parabola

https://www.mathsisfun.com/geometry/parabola.html

STEP 2: Recall what is the vertex of a parabola

https://www.qalaxia.com/viewDiscussion?messageId=5d14217d7ae99744ef6d358d

The **vertex** of a parabola is the point at the intersection of the parabola and its line of symmetry.

For a parabola whose equation is given in standard form y = ax^{2} + bx + c

, the vertex will be the minimum (lowest point) of the graph if *a*>0

and the maximum (highest point) of the graph if *a*<0

.STEP 3: Vertex form

The vertex form of a parabola is y = a(x-h)^{2} + kwhere (*h*,*k*)

is the vertex. The variable *a* has the same value and function as the variable in the standard form. If *a* > 0 (positive) the parabola opens up,

and if *a* < 0 (negative) the parabola opens down.

More on what is the vertex form of a parabola

https://mathbitsnotebook.com/Algebra1/Quadratics/QDVertexForm.html