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Question 70615: ah help meeeeeee :[[ it says determine whether each parabola opens upward,downward,left or right.
1) y=-6x[squared]
2) 2x+6y[squared]=0
THEN, it says identify the focus and the directix of the graph of each equation
:(
y=-8x[squared]
x-5y[squared]0
thanks guys :(
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1) y=-6x[squared]
The negative forces the y-values to go down; so it opens down.
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2) 2x+6y[squared]=0
x=-3y^2
The negative forces the x-values to go to the left; so it opens to the left
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THEN, it says identify the focus and the directix of the graph of each equation
:(
y=-8x^2
Rewrite as (x-0)^2=(-1/8)(y-0)
4p=-1/8
p=-1/32
The vertex is at (0,0)
The parabola opens down because of the negative.
So the focus is at (0,-1/32)
The directrix is y=1/32
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x-5y[squared]=0
x-5y^2=0
5y^2=x
y^2=(1/5)x
(y-0)^2 = (1/5)(x-0)
4p=1/5
p=1/20
vertex=(0,0)
The parabola opens to the right, so:
focus at (1/20,0)
directrix: x= -1/20
Cheers,
Stan H.
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