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Problem with solver functions - any solver function fails trying to find a zero on a function... - Messages

#1 Posted: 9/18/2023 11:31:30 AM
Oscar Campo

Oscar Campo

126 likes in 301 posts.

Group: Moderator

Here is a problem I found trying to solve a simple engineering question.


NoSolution.png

Please see attached file: Problem with solvers.sm (90 KiB) downloaded 270 time(s).
#2 Posted: 9/18/2023 9:17:56 PM
overlord

overlord

566 likes in 1,339 posts.

Group: Moderator

Sorry I don't have maxima.
Equations are solved with FindRoot().

I also had to make some alterations.
Original y(x) function has unit mismatch.
Solvers don't like direct usage of if() or cases().
You can detect it with Unknowns().
If it doesn't produce a result, there is a problem.

Here is your file solved.

Regards

Problem with solvers_solved.sm (95.81 KiB) downloaded 268 time(s).
5 users liked this post
Oscar Campo 9/18/2023 9:19:00 PM, churichuro 9/18/2023 10:05:00 PM, NDTM Amarasekera 9/18/2023 11:04:00 PM, ioan92 9/19/2023 5:38:00 AM, Alvaro Diaz Falconi 9/19/2023 7:28:00 AM
#3 Posted: 9/19/2023 8:53:43 PM
overlord

overlord

566 likes in 1,339 posts.

Group: Moderator

I assumed C.1 and C.2 has same units.
Maybe I was wrong at that conclusion.
Worksheet below find a solution between 4-6.
This may be the correct result.
Sorry if I made a huge mistake.

Regards

Problem with solvers_revisited.sm (105.7 KiB) downloaded 264 time(s).

Click to enlarge
2 users liked this post
Oscar Campo 9/19/2023 9:24:00 PM, Alvaro Diaz Falconi 9/20/2023 1:14:00 PM
#4 Posted: 9/19/2023 9:24:06 PM
Oscar Campo

Oscar Campo

126 likes in 301 posts.

Group: Moderator

Perfect! Thanks for your cooperation!
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