Question

HELP! Find the vertex and directrix of the parabola.
x^2 + 2x - 4y + 17 = 0
Please show work

Answer 1

@mathstudent55 @RadEn

Answer 2

you'd need to factor the equation from a standard form to "vertex form"
http://www.mathwarehouse.com/geometry/parabola/images/standard-vertex-forms-thumb.png

Answer 3

so
$$
x^2+2x-4y+17=0 \\
(x^2+2x+\boxed{\color{red}{?}}^2)+17 = 4y
$$
what number would you need there to get a "perfect square trinomial"?

Answer 4

I figured out out, thanks though!