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1. y= 1/-32 y^2
2. x^2=-8y

2007-12-28 06:09:36 · 6 answers · asked by Anonymous in Science & Mathematics Mathematics

Number 1. is actually x= 1/-32 y^2

2007-12-28 07:03:23 · update #1

6 answers

1. x = 1/(4p) y², or y² = 4px
focus: (p, 0)
directrix: x = -p
axis of symmetry: y = 0

x = 1/(-32) y²
4p = -32
p = -8
focus: (-8, 0)
directrix: x = 8
axis of symmetry: y = 0

2. y = 1/(4p) x², or x² = 4py
focus: (0, p)
directrix: y = -p
axis of symmetry: x = 0

x² = -8y
4p = -8
p = -2
focus: (0, -2)
directrix: y = 2
axis of sym: x = 0

2007-12-28 06:25:40 · answer #1 · answered by a²+b²=c² 4 · 0 0

With y = x^2 / 20 fixing the equation for y = 0, the x fee is 0, giving the vertex (0,0). And x^2 = 20y reveals the concentration x^2 = 4py...p = 5 giving the concentration = (0.5) for this reason the "equidistant" directix is the line y = -5. With the x fee = 0 interior the vertex, the equation of the axis of symmetry will become x = 0.

2016-10-20 04:53:47 · answer #2 · answered by ? 4 · 0 0

Your 1st question makes no sense. You have copied the problem incorrectly

x^2= -8y
This is of the form x^2 = 2py , where p = -4
The vertex is at the origin.
The focus is at (0,p/2) = (0, -2)
The directrix is at y = -p/2 = 2
the axis of symmetry is the y-axis.

2007-12-28 06:23:48 · answer #3 · answered by ironduke8159 7 · 0 0

1. Did you mean x^2 instead of y^2?
2.Vertex form: y = 1/-8(x^2)
vertex: 0,0
a = 2 because 1/4a = -1/8
parabola opens down, so directrix is above and focus below
y=2 directrix
focus below (0,-2)
axis of symmetry x=0 because x-coordinate of vertex 0

2007-12-28 06:21:31 · answer #4 · answered by digit 1 · 0 1

x² = -8y
y = (-1/8)x²

Take the first derivative:
y' = -(1/4)x
y' = 0   ⇒   x = 0
axis of symmetry: x = 0

2007-12-28 06:24:36 · answer #5 · answered by DWRead 7 · 0 0

Make sure that
f(2a-x)=2b-f(x)
where a and b are the coordinates of the focus .

2007-12-28 06:26:43 · answer #6 · answered by Anonymous · 0 0

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