SOLUTION: Give the vertex, focus, directrix, and the distance across parabola at focus, and then graph the parabola. y^2-8x-2y-15=0

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Give the vertex, focus, directrix, and the distance across parabola at focus, and then graph the parabola. y^2-8x-2y-15=0      Log On


   

Question 188599: Give the vertex, focus, directrix, and the distance across parabola at focus, and then graph the parabola.
y^2-8x-2y-15=0
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
8x=%28y%5E2-2y%2B1%29-1-15
:
8x=%28y-1%29%5E2-16
:
x=1%2F8%28y-1%29%5E2-2
:
vertex is at (-2,1)
:
1/4p=1/8--->4p=8-->p=2
:
focus is at (0,1) and directrix is x=-4
:
distance across parabola at focus is 4p 4(2)=8
:
graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Csqrt%288x%2B16%29%2B1%29