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? asked in Education & ReferenceHomework Help · 7 years ago

One algebra questions, please help me!?

Determine the equation of the parabola in the form y=ax2 + bx + c given the focus (2, 5) and directrix y=3

1 Answer

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  • 7 years ago

    the vertex is midway between the focus and the directrix

    ___ it is located at (2,4)

    the focus is above the vertex, so the parabola opens upward

    using the vertex form ___ y = a (x - 2)^2 + 4

    ___ the a coefficient is equal to 1 / (4p) ___ where p is the distance from the vertex to the focus

    ___ in this case, y = ¼ (x - 2)^2 + 4

    y = ¼ x^2 - x + 5

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