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.
You will want to use one strategy when the
function is given in
vertex form
. The reason this is called the
vertex form is because the
vertex is at the
point (h, k). Notice that the value of h is the opposite of what it is in the function, but the value of k has the same sign. So when a
function is already presented in this form, the
vertex is found simply by looking at the numbers in the function.
You will want to use a different strategy when the
function is given in standard form
. You can either use a formula or manipulate the
function into
vertex form. All strategies will be shown in the examples below.