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-MFra-21-Topaz II
21-Topaz II
January 12, 2016
Solved

The usual problem with the imaginary unit.

  • January 12, 2016
  • 2 replies
  • 3091 views

Hello everyone,

What can I do to prevent this?

in order to have a result, I had to consider the operators as variables.

Thank you for all.

F. M.

transverse laplacian.jpg

    Best answer by Werner_E

    This ist the first time in the sheet you show where you are using complex entries and so its the first time you experience the difference between conjugate or not.

    I am not willing to retype but I guess you would get the result you expect if you use one of the two methods I showed above (transpose the first factor OR conjugate the second).

    Regards, Werner

    2 replies

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    January 12, 2016

    This is what it looks like in Mathcad 11:

    (I was wondering why you got j instead of i in the result:

    That happens only if j is symbolically undefined.)

    Success!
    Luc

    W
    Werner_E25-Diamond I
    25-Diamond I
    January 12, 2016

    LucMeekes wrote:

    (I was wondering why you got j instead of i in the result:

    That happens only if j is symbolically undefined.)

    No, you can switch between i and j in the result format dialog:

    L
    LucMeekes23-Emerald IV
    23-Emerald IV
    January 12, 2016

    That option is available in Mathcad 11, but it doesn't affect the symbolic results, only the numeric:

    Luc

    W
    Werner_E25-Diamond I
    25-Diamond I
    January 12, 2016

    I am not sure why you think that Mathcad is doing anything wrong.

    It correctly complies with the definition of the dot product of vectors with complex entries:

    See here, for instance: -> Dot product - Wikipedia, the free encyclopedia

    To get what you obviously want to see, you would either have to use the matrix product (multiply a 1x3 row vector with a 3x1 column vector) or use the conjugate of the second vector of the dot matrix produkt:

    So for your first "wrong" example: 

    > >  in order to have a result, I had to consider the operators as variables.

    Sorry, but I don't understand what you mean by that!?

    Regards Werner

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    -MFra-21-Topaz IIAuthor
    21-Topaz II
    January 12, 2016

    transverse laplacian 1.jpg

    Thank you for your kind attention and response that will be, definitely, the right one.

    heartfelt greetings

    W
    Werner_E25-Diamond IAnswer
    25-Diamond I
    January 12, 2016

    This ist the first time in the sheet you show where you are using complex entries and so its the first time you experience the difference between conjugate or not.

    I am not willing to retype but I guess you would get the result you expect if you use one of the two methods I showed above (transpose the first factor OR conjugate the second).

    Regards, Werner

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