how to simplify an expression with both variables and numbers

[myang]

Hi All,

This is my first time using Mathcad...... I have this problem which seems to be not hard, however I just can't figure out..........

Would anyone like to help me out here? I've include text explanation of my problem in the attached file.

Many thanks in advance!

Mingyu

[ValeryOchkov]

May be this help you:

[myang]

Thank you, Valery. Reminds me that I need to make expression as function of unspecified variables.

[AlanStevens]

Does the attached help?

Alan

[myang]

Thank you very much, Alan. It's very helpful. Learn a lot from your tips. But please allow me to ask another question.........

I runned your attached file but yours stopped at the calculation of C with no result.

This happened to my original file as well, but mine gave me something as below. It just fails to extract the imaginary part of Ztot.....It doesn't make sense to me as it's able to get the real part....

[RichardJ]

Hard to be sure without seeing the file, but if you click on Im(Ztot) you will probably see a multiplication between the Im and the parenthesis, so it sees Im as a variable, not a function name.

[myang]

Richard,

Thank you for the reminder......But why does this happen and how to correct this? This pic is what happened when I tried to extract the imaginary part.... I attached my file. Could you help me correct it please? Thanks a lot.

[RichardJ]

I don't see this problem. What version of Mathcad are you using?

[myang]

It's Mathcad14. You mean it runs okay in your computer?

[RichardJ]

Yes, it runs fine for me.

[myang]

All right....I think I may need to change a computer and run it again.....But thank you very much for helping me figure out the problem.

[RichardJ]

It's more likely to be your version of Mathcad than the computer. "Invalid pointer" sounds like a bug to me.

[myang]

Could you provide me the screenshot of the expression of the Imaginary part please? I think if I got the result of that, I would be able to complete my calculation......Thank you

[AlanStevens · Accepted solution]

Here's a screenshot:

I've attached a pdf printout (though you will have to line up pages 3 and 4 with 1 and 2 respectively.

Alan

[myang]

Thank you very much! you help a lot.