Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

Find the equation of the parabola that passe through these three points?

Three points

(-3,3root3 - 4), (0,-4), and (3, 3root3 - 4)

form the vertices of an equilateral triangle. Find the equation of the parabola that passes through these three points.

3 Answers

Relevance
  • JG
    Lv 5
    1 decade ago
    Favorite Answer

    Note by symmetry that (0,-4) is the vertex.

    So y = ax^2 + bx - 4

    and since the vertex is on the y axis, b=0 as well

    So y = ax^2 - 4

    substitute in the third point to find a

    a*3^2 - 4 = 3root3 - 4

    a = root(3)/3

    So the parabola is

    y = root(3)x^2/3 - 4

  • 1 decade ago

    x-coordinate of (0, - 4) is midway between the x-coordinates of the remaining two points. Hence, it is the vertex. Hence, its equation is of the form,

    x^2 = a(y + 4)

    as (- 3, 3√3 - 4) lies on the parabola,

    (- 3)^2 = a (3√3 - 4 + 4) => a = √3

    => equation of the parabola is

    x^2 = √3(y + 4)

  • Erika
    Lv 4
    4 years ago

    submit to in suggestions that the final equation for a parabola is y = ax^2 + bx + c to place in writing the equation, you're able to desire to calculate a, b, & c For which you're able to desire to create 3 equations with 3 unknowns Plug the given coordinates (each and each factor) into y = ax^2 + bx + c Then, sparkling up the equipment for a, b, & c to place in writing the asked equation... artwork to do...

Still have questions? Get your answers by asking now.