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Thread: Maths Question

  1. #1
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    I have a calculation in a procedure:

    CD = (E - (2 * .286 * A)) / 2 + (M * A / PI) / 2

    E A & M are given.

    but I have situations where I need to calculate A when CD E & M are known.

    Can someone rewrite the equation for me please, its making my brain hurt!
    "Heading for the deep end"

  2. #2
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    I hope I have not made any silly mistakes...

    CD = (E-(2 * .286 * A)) /2 + (M *A/PI)/2

    2 * CD = E-(2 * .286 * A) + (M *A/PI) Multiply both sides by 2

    = E- A*(2 * .286) + A*(M *1/PI)

    = E-A*((2 * .286 ) - (M *1/PI)) Bring the common factor of A to the front

    (2*CD) -E = -A*((2 * .286 ) - (M *1/PI)) subtract E from both sides

    E-2*CD = A*((2 * .286) - (M * 1/PI)) multiply both sides by -1

    A = (E- 2*CD)
    / ((2 * .286) - (M * 1/PI))
    Regards
    John



  3. #3
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    Quote Originally Posted by weyrman View Post
    I have a calculation in a procedure:

    CD = (E - (2 * .286 * A)) / 2 + (M * A / PI) / 2

    E A & M are given.

    but I have situations where I need to calculate A when CD E & M are known.

    Can someone rewrite the equation for me please, its making my brain hurt!
    As an alternative, you could use the Solver function to give you the value of A that gives the value of CD you require.

    Think of it as en 'engineering' solution rather than a mathematical one.

  4. #4
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    John,

    Many thanks, your maths was spot on!

    Gfamily,

    I've never played with solver before but thanks for the suggestion.
    "Heading for the deep end"

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