The usual problem with the imaginary unit.

[-MFra-]

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.

[LucMeekes]

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

[Werner_E]

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:

[LucMeekes]

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

Luc

[Werner_E]

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

[-MFra-]

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

heartfelt greetings

[Werner_E · Accepted solution]

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

[-MFra-]

Thanks Werner, you're right, it was a distraction not considering the complex conjugate. You have solved the puzzle.

  You are the best!