# Thread: name for the form of an equation

1. ## name for the form of an equation

Hi;
I know standard form, vertex form and intercept form of quadratics.

but I don't know what this form is called (x - h)^2 = 4a(y - k)

Thanks.

2. ## Re: name for the form of an equation

it's a slightly modified vertex form

vertex form would be

$y = \dfrac{1}{4a}(x-h)^2+k$

3. ## Re: name for the form of an equation

The form $(x - h)^2 = 4p(y - k)$, is a “standard” form written with information to locate the parabola’s focus and directrix ... the focus is $(h, k + p)$ and the directrix is $y = k - p$