Hello I just need a little help, thanks (I did try to answer it so please be nice)
What is the equation of a parabola with (−1,−3) as its focus and y = 1 as its directrix?
My answer-> (x+1)^2-4
I dont know if I'm right though
+128407
Focus = ( -1, - 3)
Directrix ... y = 1
The vertex will lie at (-1 , [ -3 + 1] / 2 ) = ( -1, -2/2 ) = ( -1, -1)
So, p = -2 ......and we have
4p ( y + 1) = (x + 1)^2
4 (-2) ( y + 1) = ( x + 1)^2
-8 ( y + 1) = (x + 1)^2 multiply through by -1/8
y + 1 = (-1/8)(x + 1)^2 subtract 1 from both sides
y = -(1/8)(x + 1)^2 - 1
