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Math Help - How do i reduce this matrix to echelon form?

  1. #1
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    How do i reduce this matrix to echelon form?

    How do i reduce this matrix to echelon form?



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    Last edited by mr fantastic; July 3rd 2010 at 04:54 AM. Reason: Copied title into main body of post.
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  2. #2
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    Quote Originally Posted by adam_leeds View Post
    How do i reduce this matrix to echelon form?



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    Do row operations. What have you tried? Where are you stuck?
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    Quote Originally Posted by mr fantastic View Post
    Do row operations. What have you tried? Where are you stuck?
    I thought one of the rows had to start with one and make this the top one, but none of them don't?
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    Quote Originally Posted by adam_leeds View Post
    I thought one of the rows had to start with one and make this the top one, but none of them don't?
    Are you familiar with the three basic row operations? If so, I don't see what the trouble is.
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    Quote Originally Posted by mr fantastic View Post
    Are you familiar with the three basic row operations? If so, I don't see what the trouble is.
    can you divide the top one by 4?
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  6. #6
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    Yes, multiplying (or dividing) each number in a row by a fixed number (not dividing by 0, of course) is a row operation.
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  7. #7
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    Quote Originally Posted by HallsofIvy View Post
    Yes, multiplying (or dividing) each number in a row by a fixed number (not dividing by 0, of course) is a row operation.
    ok so its

    1 0 1/4
    2 3 -3
    2 -1 4
    0 1 2

    becomes

    1 0 1/4
    0 3 -7/2
    0 -1 7/2
    0 1 3/2

    Is this right? I thought they had to start with 1 to be in echelon form?
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  8. #8
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    Quote Originally Posted by adam_leeds View Post
    ok so its

    1 0 1/4
    2 3 -3
    2 -1 4
    0 1 2

    becomes

    1 0 1/4
    0 3 -7/2
    0 -1 7/2
    0 1 3/2

    Is this right? I thought they had to start with 1 to be in echelon form?
    Assuming all calculations are correct, it is not quite finished.

    I suggest you will benefit by going to your class notes or textbook and reviewing this material more thoroughly.
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  9. #9
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    Well, the first row does start with 1. Now, do the same thing, starting with the second row- you can treat it as if it were a 2 by 3 matrix now.
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    Quote Originally Posted by mr fantastic View Post
    Assuming all calculations are correct, it is not quite finished.

    I suggest you will benefit by going to your class notes or textbook and reviewing this material more thoroughly.
    My notes are rubbish

    How do i do it, can you tell me please.
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  11. #11
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    Quote Originally Posted by adam_leeds View Post
    My notes are rubbish

    How do i do it, can you tell me please.
    R4 --> R4 + R3 should be obvious.

    As for your notes, that's a reason why educational institutes build libraries ....
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  12. #12
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    Quote Originally Posted by mr fantastic View Post
    R4 --> R4 + R3 should be obvious.

    As for your notes, that's a reason why educational institutes build libraries ....
    So :


    1 0 1/4
    0 3 -7/2
    0 -1 7/2
    0 0 5

    Is that complete now?
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  13. #13
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    Quote Originally Posted by adam_leeds View Post
    So :


    1 0 1/4
    0 3 -7/2
    0 -1 7/2
    0 0 5

    Is that complete now?
    No, please think more carefully about the replies you have been given and learn something from them. From what you have been shown so far, it should be clear by now that there is something can be done with row 2 and row 3.
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