Tom K. answered 05/15/21
Knowledgeable and Friendly Math and Statistics Tutor
As the y term is squared and the x term is linear, this is a parabola.
y^2 - 6y = 8x + 23
Complete the square
y^2 - 6y + 9 = 8x + 23 + 9
(y-3)^2 = 8x + 32 = 8(x+4)
To determine the directrix and focus, we write
(y-3)^2 = 4*2(x+4)
The vertex is (-4, 3)
The directrix is x = -4 -2
The directrix is x = -6
The focus is (-4 + 2, 3) = (-2, 3)
The axis of symmetry is y = 3