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Laplace Transform Bug??
09-11-2015, 07:39 AM
Post: #1
Laplace Transform Bug??
Hey dear people Smile I think the Laplace Transform has a little bug o Am I making a mistake?? Confused


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09-11-2015, 12:08 PM
Post: #2
RE: Laplace Transform Bug??
There a missing evalf at the end.
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09-15-2015, 08:52 PM
Post: #3
RE: Laplace Transform Bug??
Hello,
so does this mean the Prime does not always return an exact value in CAS mode?
Is this a bug or just a matter of usage?
I get a simelar issue with this line:

solve(TAN(x)=1,x,(-pi/2)..(pi/2))
It outputs: 0.785398163397

If i use the exact() command I get:
(286602)/(364913) as the result.

Basicly this is pi/4. The line above is not.
It is almost. I think I wouldn't even care.
But shouldn't it say the result ist pi/4 instead of a the fraction?
Another thing that I noticed is that if I try this in degree mode I get 45° which is the exact answer I would expect. But the output changes there too if I do not use the exact() command.
Using it exact() the output is: 45°
Without: 45.°
So there is a dot at the end.

I thought I may share this little things. In my opinion this are no big bugs or something similar.
Usually I would not care about something like this because I do not think I will ever have to use such precise numbers.

Greetings
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09-15-2015, 09:09 PM
Post: #4
RE: Laplace Transform Bug??
(09-15-2015 08:52 PM)MrMcChicken Wrote:  Hello,
so does this mean the Prime does not always return an exact value in CAS mode?
Is this a bug or just a matter of usage?
I get a simelar issue with this line:

solve(TAN(x)=1,x,(-pi/2)..(pi/2))
It outputs: 0.785398163397

If i use the exact() command I get:
(286602)/(364913) as the result.

Basicly this is pi/4. The line above is not.
It is almost. I think I wouldn't even care.
But shouldn't it say the result ist pi/4 instead of a the fraction?
Another thing that I noticed is that if I try this in degree mode I get 45° which is the exact answer I would expect. But the output changes there too if I do not use the exact() command.
Using it exact() the output is: 45°
Without: 45.°
So there is a dot at the end.

I thought I may share this little things. In my opinion this are no big bugs or something similar.
Usually I would not care about something like this because I do not think I will ever have to use such precise numbers.

Greetings

I may be mistaken but I believe that if you want exact answers, then you should avoid supplying guesses or search intervals. solve(tan(x)=1,x) results in pi/4

The exact() command does not seem to work because the input is an approximation of pi/4. You may find the QPI program useful in such instances.

Graph 3D | QPI | SolveSys
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09-16-2015, 06:00 PM
Post: #5
RE: Laplace Transform Bug??
(09-15-2015 09:09 PM)Han Wrote:  I may be mistaken but I believe that if you want exact answers, then you should avoid supplying guesses or search intervals. solve(tan(x)=1,x) results in pi/4

The exact() command does not seem to work because the input is an approximation of pi/4. You may find the QPI program useful in such instances.

Thanks a lot! I guess there is still a lot so learn about this calculator, I got mine last week. Luckily there are some hekpful people here Smile.
By the way: Thanks for your cool 3D graphing app!
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