How do you graph (y-9)^2 = -8(x+5)?

1 Answer
Apr 8, 2017

Please see below.

Explanation:

The equation is of the form x=a(y-k)^2+h, whose vertex is (h,k) and axis of symmetry is y-k=0, as it can be written as

x=-1/8(y-9)^2-5 ............................(A)

and its vertex is (-5,9) and axis of symmetry is y=9

Let us select a few points with ordinate around 9,

say {1,3,5,7,11,13,15,17}

Putting these as y in (A), we get values of x as

{-13,-9.5,-7,-5.5,-5.5,-7,-9.5,-13}

Joining these sets of points i.e. (-13,1), (-9.5,3), (-7,5), (-5.5,7) (-5.5,11), (-7,13), (-9.5,15) and (-13,17) and we get the parabola.

graph{(y-9)^2=-8(x+5) [-33.59, 6.41, -1.12, 18.88]}