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1-Visitor
May 18, 2014
Solved

I must be doing something silly...

  • May 18, 2014
  • 5 replies
  • 1886 views

I'm getting a "this variable is undefined". I don't know why...It's Mathcad 15..probably something simple I'm overlooking, but I don't see it!

Hope someone can point it out, and I will happily say "D'Oh!"

Best answer by Werner_E

You have written "Given" twice. Delete one og them, preferably the first, and you get a solution.

Find attached a version without the need for copy and paste.

5 replies

DanJoffe1-VisitorAuthor
1-Visitor
May 18, 2014

It's funny...I just cut and pasted this to a new file, and it solves it with no complaints!...oh well..

12-Amethyst
May 18, 2014

You have an extra "Given" statement at the top of the file. Removing it allowed program to run.

DanJoffe1-VisitorAuthor
1-Visitor
May 18, 2014

D'Oh!

Thanks!

Werner_E
Werner_E25-Diamond IAnswer
25-Diamond I
May 18, 2014

You have written "Given" twice. Delete one og them, preferably the first, and you get a solution.

Find attached a version without the need for copy and paste.

Werner_E
25-Diamond I
May 18, 2014

Forgot to attach the file and have deleted it.

Anyway here is a fully numerical approach.

It seems that with the values you provided at the end of your first sheet there is no solution where all three resistors woul have positive values. Anything wrong with the equations??

See attachment

EDIT: Found the symbolic solution I mentioned and compared its results to the numerics. See new attachment.