Skip to main content
J
jfluckey1-Visitor
1-Visitor
July 14, 2011
Solved

Mathcad provides incorrect solution

  • July 14, 2011
  • 1 reply
  • 14382 views

Mathcad is adding a very small number to my results. There is no explaination for it. I am using Mathcad 14.

I have attached both the Mathcad file and a PDF (in case you are not running v14).

If you don't feel like downloading the attachments, this is the jist of what is happening:

Why would Mathcad add in that 10^(-14)? The problem is I want to do something similar to the following: . My equations don't work with imaginary numbers!

I tried increasing the Worksheet Options to 1e-020 for both TOL and CTOL and neither corrected the problem. What is happening?!??!?!

Best answer by RichardJ

Settings.png

1 reply

J
jfluckey1-VisitorAuthor
1-Visitor
July 14, 2011

I copied equations from Mathcad into the post which showed fine before submitting, but they didn't show up after submitting. So my post may be a little confusing. I also did not see a button to edit my original post. Therefore, please see the following correction:

If you don't feel like downloading the attachments, this is the jist of what is happening:

hn = 99*ft

n = 10

hincr = hn/n = 9.900000000000000000*ft

hincr*10 = 9.900000000000001000*ft

Why would Mathcad add in that 10^(-14)? The problem is I want to do something similar to the following: sqrt(hn-hincr*10)= imaginary number. My equations don't work with imaginary numbers!

M
MikeArmstrong1-Visitor
1-Visitor
July 14, 2011

Looks like a bug to me.

Mike

J
jfluckey1-VisitorAuthor
1-Visitor
July 14, 2011

I thought so too. There is also no way around it that I have found. I tried to redefine variable that had the anomaly, "x", to Floor(x,0.00001*ft), yet the error is persistent.

Terms & ConditionsAccessibility statement