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Homework Help: Parametric equation help

  1. Mar 7, 2006 #1
    hi apologise if this is in the wrong forum :)

    my lecturer has told me that i need to be able to express parametric equations as a cartesian equation in my exam later this month. my mind boggles !

    here is an example i have found.

    Express the parametric equations x = 2 t - 2 and y = 3 t - 2 as a Cartesian equation in just x and y.

    any help would be great!

    kind regards lakitu :)
     
  2. jcsd
  3. Mar 7, 2006 #2

    Integral

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    Solve your x and y equations for t. Then since both are equal to to t you can eliminate the t.
     
  4. Mar 8, 2006 #3
    hi thank you i will give that a go :)

    lakitu
     
  5. Mar 8, 2006 #4
    x = 2 t - 2 -----------------(1)
    y = 3 t - 2 -----------------(2)

    multiply (1) by 3 and (2) by 2.

    3x = 6 t - 6 -----------------(3)
    2y = 6 t - 4 -----------------(4)

    we can now eliminate t from the two eqns by subtracting (4) from (3)

    3x - 2y = -6 + 4
    3x - 2y = -2


    how does this look to you ?
     
  6. Mar 8, 2006 #5

    Hootenanny

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    Looks good to me.
     
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