Question 619253: Find vertex, focus, and directrix of the parabola. 1/2y^2 +18x=0
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! Find vertex, focus, and directrix of the parabola.1/2y^2 +18x=0
Given parabola opens leftwards
Its equation: (y-k)^2=-4p(x-h), (h,k)= (x,y) coordinates of vertex
1/2y^2 +18x=0
1/2y^2 =-18x
y^2=-36x
vertex: (0,0)
axis of symmetry: y=0 or x-axis
4p=36
p=8
focus: (0-p,0)
=(0-8,0)
=(-8,0)
..
Directrix: x=8 (p units to the right of vertex on the axis of symmetry)
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