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Question 80562: plaese help me out with is thank u
The following equation is a circle.
y=x^2-6x+1
True
False
Question 4
The following equation is a circle.
12x^2+12y^2=36
True
False
Question 5 6 points Save
What is the center of the following circle?
Enter your answer as an ordered pair with no spaces.
(x,y)
x^2+y^2-4x+8y-3=0
Question 6
Which way does the following parabola open?
x=-4y^2+8y-2
up
down
left
right
Question 7
What is the vertex of the following parabola?
Enter your answer as an ordered pair with no spaces.
(x,y)
x=-4y^2+8y-2
Question 8
What is the focus of the following parabola?
x=-4y^2+8-2
Question 9
What is the equation of the directrix of the following parabola?
x=-4y^2+8y-2
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! The following equation is a circle.
y=x^2-6x+1
False : it is a parabola
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Question 4
The following equation is a circle.
12x^2+12y^2=36
True : because the coefficients of x^2 and y^2 are the same.
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Question 5 6 points Save
What is the center of the following circle?
Enter your answer as an ordered pair with no spaces.
(x,y)
x^2+y^2-4x+8y-3=0
Complete the square for the x-terms and the y-terms separately:
(x^2-4x+4) + (y^2+8y+16) = 3+4+16
(x-2)^2 + (y+4)^2 = 23
Center at (2,-4)
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Question 6
Which way does the following parabola open?
x=-4y^2+8y-2
left : because it follows the form x=ay^2 where a is negative.
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Question 7
What is the vertex of the following parabola?
Enter your answer as an ordered pair with no spaces.
(x,y)
x=-4y^2+8y-2
Complete the square on the y-terms:
x+2-4=-4(y^2-2y+1)
x-2 = -4(y-1)^2
Vertex at (2,1)
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Question 8
What is the focus of the following parabola?
x=-4y^2+8-2
Same as above resulting in the form
x-2 = -4(y-1)^2
Therefore 4p=-4 and p=-1
So the focus is 1 to the left of the vertex or at (1,1)
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Question 9
What is the equation of the directrix of the following parabola?
x=-4y^2+8y-2
Same work as above but the directrix is 1 to the right of the vertex:
x=3 is the directrix.
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Cheers,
Stan H.
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