Question

What is the vertex form of `y=(x+2)(x-2)`?

Answer 1

`y=x^2-4`

Explanation:

`" y has roots " x=+-2`

`"the x-coordinate of the vertex is at the midpoint of the roots"`

`rArrx_(color(red)"vertex")=(-2+2)/2=0`

`rArry_(color(red)"vertex")=(0+2)(0-2)=-4`

`"the equation of a parabola in "color(blue)"vertex form"` is

`• y=a(x-h)^2+k`

`"where " (h,k)" are the coordinates of the vertex and a is "`
`"a constant"`

`"here " (h,k)=(0,-4)" and " a=1`

`rArry=x^2-4larrcolor(red)" in vertex form"`