Why the laplace transform of a derivative not work when I added a constant value to it?

[Cornel]

Hi,

Why when I added a constant value a to a derivative I see that the laplace transform of a derivative did not work as expected? Am I doing wrong something? Or?
Prime 9 sheet attached..

[Cornel]

[LucMeekes]

It seems like the derivative of b(x) is sometimes not recognised as such.

Check the labels of your variable, especially the x'es. All your x'es should be of the same label.

Success!
Luc

[Cornel]

I checked x-es labels...they are the same:

[LucMeekes]

Still there is a different one. the (x) between brackets is a '(variable)', not a 'variable'.

If that doesn't help, file a bug report.

Success!
Luc

[Cornel]

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@LucMeekes wrote:

Still there is a different one. the (x) between brackets is a '(variable)', not a 'variable'.

If that doesn't help, file a bug report.

Success!
Luc

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Yes, but look, the laplace transform with same (x), so '(variable)' not a 'variable' run without problem when removing that constant a:

[Werner_E]

As Luc already wrote - report it as a bug to PTC support.

BTW, P9 is still a little bit better than P6 where we see this (the derivative is treated as a constant!):

EDIT: Sorry, the above was due to Prime's autolabelling bugs which were even worse in P6 than in P9. After manually labelling the variables we see

So what you experience in Prime 9 seems to be a newly (after P6) introduced bug which should be reported.

In case you are interested - the legacy engine in P6 (muPad) gives us