SOLUTION: i need help with writing equations for parabolas and eclipses the question i have in this packet im doing is: what is the equation of a parabola that opens downward and has an

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: i need help with writing equations for parabolas and eclipses the question i have in this packet im doing is: what is the equation of a parabola that opens downward and has an      Log On


   

Question 452453: i need help with writing equations for parabolas and eclipses
the question i have in this packet im doing is:
what is the equation of a parabola that opens downward and has an axis of symmetry x=-1
and from a graph how do you find the equation for an eclipse?
thank so much
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
what is the equation of a parabola that opens downward and has an axis of symmetry x=-1
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y = -(x-1)^2
graph%28400%2C300%2C-10%2C10%2C-10%2C10%2C-%28x-1%29%5E2%29
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and from a graph how do you find the equation for an eclipse?
Find the center at (h,k)
Find the length of half of the major axis: that's "a".
Find the length of half of the minor axis: that's "b".
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Write the equation:
(x-h)^2/a^2 + (y-k)^2/b^2 = 1
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Cheers,
Stan H.