Quadratic Formula

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Alex Joe Math, Period 4 Wednesday, May 28th,
2003
Our Very Special Math Project
The Quadratic Formula
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The QuadraticFormula

• -b v b2 - 4ac
• X 2a

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Quadratic Formula

• -5v41
• x 2
• x -5v41 or -5-v41
• 2 2

• x25x-4 0
• -5 v 25-4(1)(-4)
• x 2(1)

• -bvb2-4ac
• x 2a

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Explanation

• The Quadratic Formula is used to find the X-AXIS
  points on a parabola (the graph of a quadratic
  function is a parabola that opens upward if agt0
  and opens downward if alt0.).

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Why it is Important

• Quadratic Formula is important to algebra because
  it allows you to find the X roots for a
  parabola.

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Occupations

• You would use Quadratic Formula in engineering,
  electronics, and construction design.

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Real Life Example

• A real life example would be if you wanted to
  know how strong something would need to be to
  hold something else up.

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Word Problem

• The number of citizens (in millions) voting in
  each presidential election since 1824 can be
  approximated by the quadratic function
  V(t)0.0046t2 - 0.185t 3.30, where t represents
  the number of years since 1824. For her history
  project, Marcela Ruiz needed to determine in what
  year the number of voters in a presidential
  election was approximately fifty-five million.
  She used the function above, replacing V(t) with
  fifty-five.
• V(t) 0.0046t2 0.185t 3.30
• 55 0.0046t2 0.185t 3.30
• 00.0046t2 0.185t 51.7
• Marcela knew that she could use her graphing
  calculator to estimate the solutions of this
  equation, but she wondered how she could get a
  good estimate of t if she didnt have a graphing
  calculator.

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Memorization

• To memorize the quadratic formula, use the tune
  to Pop Goes The Weasel. Start with x equals
  negative b plus or minus square root of b squared
  minus four a c, all over two a.