Laplace function a bit limited

11052016, 11:42 PM
Post: #1




Laplace function a bit limited
Just got a new HP prime C series. I tried some Laplace transform derivations and the first two I picked failed, these were:
1/t which I entered as laplace (1/t, t, s) it returned undef and (1e^{t})/t entered as laplace ((1e^(t))/t, t, s) returned undef. Question is have I entered the equations incorrectly or is the CAS just limited? The 1/t in particular is a standard function to get the laplace transform of, its just 1/s^2. 

11062016, 12:40 AM
(This post was last modified: 11062016 12:44 AM by Mark Hardman.)
Post: #2




RE: Laplace function a bit limited
On my first day of Filter Design 214 I learned:
ℒ[t] = 1/s^2 https://www.wolframalpha.com/input/?i=laplace(t,t,s) Just saying... Mark Hardman Ceci n'est pas une signature. 

11062016, 01:37 AM
Post: #3




RE: Laplace function a bit limited
(11062016 12:40 AM)Mark Hardman Wrote: On my first day of Filter Design 214 I learned: Of course I know what the Laplace transform of t is. What I wanted to know was whether the calculator knew, obviously it didn't. As I said, this was surpring for such a basic transform. It suggests to me that the Cas capability at least for Laplace transforms might be limited. I shall need to try some more. 

11062016, 01:47 AM
(This post was last modified: 11062016 01:51 AM by Mark Hardman.)
Post: #4




RE: Laplace function a bit limited
(11062016 01:37 AM)hsauro Wrote: Of course I know what the Laplace transform of t is. What I wanted to know was whether the calculator knew, obviously it didn't. As I said, this was surpring for such a basic transform. It suggests to me that the Cas capability at least for Laplace transforms might be limited. I shall need to try some more. No, you said the following: (11062016 01:37 AM)hsauro Wrote: The 1/t in particular is a standard function to get the laplace transform of, its just 1/s^2. Which is demonstratively false. The CAS is telling you that there is no standard form for: ℒ[1/t] WolframAlpha agrees. https://www.wolframalpha.com/input/?i=la...1%2Ft,t,s) "(no result found in terms of standard mathematical functions)" Mark Hardman Ceci n'est pas une signature. 

11062016, 01:58 AM
(This post was last modified: 11062016 02:03 AM by hsauro.)
Post: #5




RE: Laplace function a bit limited
(11062016 01:47 AM)Mark Hardman Wrote:(11062016 01:37 AM)hsauro Wrote: Of course I know what the Laplace transform of t is. What I wanted to know was whether the calculator knew, obviously it didn't. As I said, this was surpring for such a basic transform. It suggests to me that the Cas capability at least for Laplace transforms might be limited. I shall need to try some more. My bad I apologize, don't know why I typed in 1/t ! Prime certainly can do t. Anyone one reading this thread, it's a false alarm, sorry for the confusion. 

11062016, 02:06 AM
Post: #6




RE: Laplace function a bit limited
(11062016 01:58 AM)hsauro Wrote: [quote='Mark Hardman' pid='63693' dateline='1478396852'] If any one has the power to delete threads this is one that should probably be deleted in case it inadvertently mismlead ssomeone, since the original premise is incorrect. 

11062016, 02:27 AM
Post: #7




RE: Laplace function a bit limited
You can delete threads yourself. Just click edit>full edit and on the top there is an option to delete.


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