@ecterrab 

Your answer clarifies allot. It describes in general how dsolve works and why there can be many solutions. I was looking for something like that.

My answer was only guess work, based on observations I made here and there. I did not delete it after sending when I saw your answer (to document at least where a user is right or wrong in his interpretation).

I would not have guessed to find something of interest in ?dsolve,setup. So I never consulted this page. Besides technical details I now can describe myself better as a curios standard user. However, this page rasies again the question about the difference between classificon methods, returned results and methods for ODE solving. More specifically, why is dAlembert not listed under "Methods for 1st order ODEs"? Should this be clear to the standard user?

Finally, some thoughts on PDETools. PDETools is mentionned (not only on the dsolve,setup page) in a way that it is a natural part of ODE solving. Many answers here in this forum use PDETools as well. Why should a standard user interested in ODE solving consult PDE librararies? I have not found an answer to it yet. For me, the use of PDETools sounds like a workarround for something that is not possible with ODETools. If a libraray function can be used for PDEs and for ODEs shouldn't it be part of a DETool package?

Anyway, exanding at bit more on how dsolve works and the existence of branched solutions (I doubt that many users are aware of this) could strenghten the educational aspect of Maple in the nontrivial domain of differential equations. Here Maple is my first point of reference since I want to use Maple to get solutions. The other way arround (studying ODEs with a textbook and then finding the right commands in Maple) does not make sense to me.

Maybe also of interest:

https://www.mapleprimes.com/posts/220633-DMS-Degrees-Minute-Seconds-To-Decimal-Conversion

Not clear what you want to simplify. You could combine the roots under certain assumptions.

combine(sqrt(2)*sqrt(a[5])/sqrt(a[4])) assuming (0 < a[5], 0 < a[4])

@Thomas Richard 

That works. The tricky bit is when the spacecurve is not an explicit function of time and generated by numerical integration. If I understand @mmcdara solution correctly, he solves a sequence of IVP where each solution generates the initial values for the subsequent IVP. Quite some coding required for numerical solutions.
Thank you

@mmcdara 

That is a step in the right direction. The colorsheme option is of value when the animation is stopped.
Thank you!

Nice examples. 

I played a bit with integration methods

Used for the plot above:

sol := dsolve({sys, x(0) = 1.1, y(0) = 1.1, z(0) = -0.01}, {x(t), y(t), z(t)}, numeric);
sol2 := dsolve({sys, x(0) = 1.1, y(0) = 1.1, z(0) = -0.01}, numeric, method=classical[foreuler],maxfun=100000);
p1:= odeplot(sol, [x(t), y(t), z(t)], t = 0 .. 50, axes = boxed, numpoints = 50000, labels = [x, y, z], title = "Thomas Attractor", color = red):
p2:=odeplot(sol2, [x(t), y(t), z(t)], t = 0 .. 50, axes = boxed, numpoints = 50000, labels = [x, y, z], title = "Thomas Attractor",color=blue):
plots:-display(p1,p2,title="rkf45 (red) vs. forward Euler (blue)");

Before the loop, try

interface(warnlevel=0)

After the loop you can set it back to 3.

@Ronan 

I have two Laptops connected via UBS docs to large monitors. My current observations have be made in this configuration. Can't say yet if this is also valid in laptop mode without mouse. I will have an eye on it next time I am traveling.

I have also enabled windows screen saver. That you don't see it fits to my observation.

Thanks for sharing this detail

 @rlopez @Carl Love 

I have found a way to disappear submenus: Power buton -> sleep

Interstingly, turning of by hibernation did not show the effect. Submenus did not dissapear.

Can some confirm that sleep triggers the effect? If so, developers should be informed.

Have you tried it and got any usefull answer? Look at this

This is what you get when you ask Chat GPT directly and it is not working in Maple. Maple's AI assistant is better in the sense that it does not give you wrong commands (for this example). You get trig identities for simplifcation but no commands.

@Carl Love  @Thomas Richard 

I have never seen combine from this perspective (making arguments more complicated). For me it was so far the inverse operation of expand, which I learned now is not the case for ordinary polynominals. I did not pay attention to this.

Expand most of the time enlarges expressions in size, which is not the case for the example above. Common sense interpretation fails in this case.

Altough I do not often use the context pannel, it gives a quick overview about "what could be tried else" before consulting help pages. In this case the context pannel was indeed proposing the effective command, which I did not try because I though it must be expand,trig (i.e. the opposite of combine,trig). I am not sure if expand,trig is needed at all in newer versions of Maple.

In this case even combine,trig is not needed but offered by the context pannel:

   Using commands expand does the inverse of combine

   Using the context pannel expand does the inverse of combine,trig

I still think simplify or simplify,size or simplify,trig are worth discussing as supplementary ways but leave this open for annother time.

Thank you for clarifying.

@nm 

Actually I tried simplify first. I missed to say that to expand cos(x)^2 one must use combine,trig, which is also counter intuitive and feels inverted. New user should at least get a solution from the context pannel and by doing so learning the seemingly inverted commands for this case. The context plannel is a good way to learn Maple.

As you said, it required some tries for me to get the desirded transformation.

@nm  I used

https://learn.microsoft.com/en-us/sysinternals/downloads/process-explorer

@nm 

You said:

If the problem with the graphics adaptor, then I would see this in other applications, right? But it is only Maple which does this. But restarting Maple fixes it for few hrs until it happens again.

I don't think so. You can expect to see it in other applications running under under the same JDK

which interfaces to the operating system. E.g. an older version of Maple.

I would check also whether the drivers are updated. (If this has an effect, it is not Java) 

If the same system did not show this before, I think it has something to do with the windows installation.

Could you check in the device manager which graphic apaters are available and properly installed.

If NVIDIA is installed you can check/modify in the NVIDIA control panel prefered graphic processors.

In the taskmanager you could also check if a GPU is used for Maple.