Find the vertex, focus, and directrix of the parabola.
x^2 - 2x + 8y + 9 = 0
x^2 - 2x +1 = -8y + 9+ 1
(x-1)^2 = -8(y-1.25)
vertex:(1,1.25)
focus:(1,-.75)
directrix: y=3.25
My teacher said that I have sign errors. I do not know where I went wrong.
2 answers
the +9 when transferred to the other side should be -9
Why did you add 1 to each side?