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Homework Help: Linear transformation

  1. Dec 16, 2012 #1
    1. The problem statement, all variables and given/known data
    You are given that T is a linear transformation from R^3 to P2, that T((1,1,-1))
    =X, and that T((1,0,-1))=X^2+7X-1. Find T(0,-5,0) or explain why it cannot be determined form the given information.

    2. Relevant equations
    None


    3. The attempt at a solution
    There is only X given, and that 's not enough to fine T(0,-5,0)
     
  2. jcsd
  3. Dec 16, 2012 #2

    LCKurtz

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    Saying that doesn't make it so. What have you tried?
     
  4. Dec 16, 2012 #3
    T((1,1,-1)) and T((1,0,-1)) should produce something close.
     
  5. Dec 16, 2012 #4

    LCKurtz

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    True. So try something.
     
  6. Dec 16, 2012 #5
    i dont knwo :(
     
    Last edited: Dec 16, 2012
  7. Dec 16, 2012 #6

    LCKurtz

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    Hint: Can you build (0,-5,0) out of what you have?
     
  8. Dec 16, 2012 #7
    C1*(1,1,-1)+c2(1,0,-1)
    C1=-5 and C2=5

    -5(1,0,1)+5(1,7,-1)=(5,30,-5)
     
  9. Dec 16, 2012 #8

    LCKurtz

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    You didn't answer my question. Can you get (0,-5,0) or not?
     
  10. Dec 16, 2012 #9
    no The question did not give the formula of the transformation
     
  11. Dec 16, 2012 #10

    LCKurtz

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    Like I said above, stating it doesn't make it so. It looks like you are just guessing in post #7. You need to show why you can or can not get (0,-5,0) that way.
     
  12. Dec 16, 2012 #11
    I am going to read textbook. Did not attend class Thanks for the hlep
     
  13. Dec 17, 2012 #12

    HallsofIvy

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    Frankly, you sound like you have never actually taken a course in linear algebra! Do you know what a "linear combination" of vectors is?
     
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