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What does the product (c/a) of a quadratic function tell you about the graph or the path of the parabola?

I don't really understand what the product even is...

2 Answers

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  • ?
    Lv 7
    2 years ago
    Favorite Answer

    Expanding a quadratic aleady solved in the form

    a(x – p)(x – q) = ax^2 – a(p + q)x + apq – 0, and then

    comparing with .. ax^2 ..+... bx .....+ c, we have

    Sum of roots p + q = -b/a, and

    Product of roots pq = c/a

    That is probably what the question meant. Compare these two quadratics.

    y = 3x^2 – 3x – 18, product of roots pq = (-2)*(3) = c/a = -18/3 = -6

    y = 2x^2 + 4x – 70, product of roots pq = (-7)*(5) = c/a = -70/2 = -35

    See these graphs for comparison.

    https://www.wolframalpha.com/input/?i=y+%3D+3x%5E2...

    The larger value for c/a with the second quadratic tells us that the path of that parabola is wider, passing through more separated roots

  • 2 years ago

    A product is the result of multiplication. c/a is not a product; it is a quotient, the result of division.

    A quadratic can be written in the form y = ax^2 + bx + c where a,b,c are constants.

    a tells you whether the quadratic curve opens up or down. When a is positive, the curve has a minimum and opens up. When a is negative, the curve has a maximum and opens down.

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