Question

How do you write `y=x^2-8x+20` into vertex form?

Answer 1

`y=(x-4)^2+4`

Explanation:

`y=[x^2-8x]+20`
`y=[(x-4)^2-16]+20`
`y=(x-4)^2-16+20`
`y=(x-4)^2+4`

Answer 2

`y=(x-4)^2+4`

Explanation:

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

`color(red)(bar(ul(|color(white)(2/2)color(black)(y=a(x-h)^2+k)color(white)(2/2)|)))`

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

`"to obtain this form use the method of "color(blue)"completing the square"`

`• " the coefficient of the "x^2" term must be 1 which it is"`

`• " add/subtract "(1/2"coefficient of the x-term")^2" to"`
`x^2-8x`

`rArry=x^2+2(-4)xcolor(red)(+16)color(red)(-16)+20`

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