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Question 144037: hello i am in 10th grade right now
and we are learing about conics
there are few problems that i do not understand
and i would really appreciate it if you could send me e-mail as soon as possible
i have a quiz this week
thank you so much!! i really appreciate it
here's the problem
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focus at (-3,4); directrix the line y=2
given this information, how do you find:
vertex (h,k) =
a (distance between focus and vertex) =
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i know that the parabola is going to open up and the formula for the
directrix line is y= k-a
and y= 2 , so that means k-a=2, but i do not know the vertex
and the value of a...
thank you for your HELP!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! focus at (-3,4); directrix the line y=2
given this information, how do you find:
vertex (h,k) =
a (distance between focus and vertex) =
----------------------------------------------------------------------
i know that the parabola is going to open up and the formula for the
directrix line is y= k-a
and y= 2 , so that means k-a=2, but i do not know the vertex
and the value of a...
--------------------------------------
When you work with conics it is always good to draw the picture
using the information you are given so you can visualize the
missing information.
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You have the focus at (-3,4) and the directrix at y =2
The vertex is always half-way between the focus and the directrix.
The y-difference between the point and the directrix is 4-2 = 2
Half that distance is 1
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So the vertex is at (-3,3)
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Cheers,
Stan H.
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