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.

Mathematics: Quadratic Relations?

Dianne dove from the 10 m diving board.

Her height, h, in meters, above the water when she is x meters away from the end of the board is given by:

h = -(x - 1)^2 + 11

What horizontal distance had she traveled when she entered the water

Answer to the nearest tenth of a meter.

Please show your work, thank you so much!

2 Answers

Relevance
  • 8 years ago
    Favorite Answer

    The given equation that relates h (= height above the water) to x (= horizontal distance from starting point) is

    h = -(x - 1)² + 11

    h = -x² + 2x + 10

    When she hits the water, h = 0, so

    0 = -x² + 2x + 10

    0 = x² - 2x - 10

    Solve this quadratic equation using the discriminant:

    √D = √( (-2)² - 4×1×(-10) ) = 6.633

    x₁ = (2 + 6.633) / (2×1) = 4.32

    x₂ = (2 - 6.633) / (2×1) = -2.32

    A negative value makes no sense in this case, so the only valid solution is

    x = 4.3 (in meters)

  • landry
    Lv 4
    4 years ago

    a polynomial of degree 2( this is, the utmost skill of the variable in that's 2) is talked approximately as a quadratic polynomial. as an occasion: x^2 + x + a million, 5x^2 + 3x., (a million/2)*x^2. if we draw the graph of a quadratic equation, we are able to verify that that's a verify talked approximately as a parabola. a quadratic equation has somewhat 2 roots ( 2 specific values of x make y akin to 0). Its graph cuts the x-axis at 2 aspects and those 2 aspects are the roots of the equation. whilst a=0, ax^2 will become 0. for this reason the polynomial will now no longer have degree 2. So, a should not be akin to 0 if the expression is to proceed to be a quadratic polynomial.

Still have questions? Get your answers by asking now.