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Intern
Posts: 45
Member Since: ‎09-29-2012
Message 1 of 8 (2,192 Views)

Differential Equations on HP Prime

I have the following differential equation: 3y -5y'=13

Subject to the initial condiction: y(0)=4

 

In the hp 50g, in RPN Mode, I create a vector with the expressions and the initial condition and invoke the desolve commnad, like this:

 

[ 3*y(x) - 5*d/dx(y(x))=10   y(0)=4]

y(x)

desolve

 

That is enough to get the following solution:

13/3 -1/3 e ^ (3/5 x)

 

The hp prime has a desolve command, but the documentation is so bad and scarse that is is almost impossible to figure out how to solve the problem above, with the initial conditions. I don't even know if it is possible.

 

Does anyone know how to do it ?

Is there better documentation available?

 

Please, don't reference the user guide. I already verified it.

 

Thanks

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Intern
Posts: 45
Member Since: ‎09-29-2012
Message 2 of 8 (2,150 Views)

Re: Differential Equations on HP Prime

Ok.. I figured out how to put the expression and the initial condition in a vector. The rest is basically the same as in the HP50g.  A better user guide is needed URGENT!

Top Student
Posts: 6
Member Since: ‎02-02-2015
Message 3 of 8 (1,168 Views)

Re: Differential Equations on HP Prime

I would sure appreciate knowing how you did that.  When I try using the 'solve|differential equation' function for anything beyond a trivial DiffEQ I get garbage (probably the right answer buried in their somewhere, but it would be easier to do the calc by hand than try to decipher the gibberish).

 

Thanks in advance!

 

 

Grad Student
Posts: 240
Member Since: ‎01-08-2009
Message 4 of 8 (1,134 Views)

Re: Differential Equations on HP Prime

Did you look at the on calc help? Both examples show setting an initial condition and neither uses the optional vector input like you found.

 

As for the desovle solutions, the way it was explained to me was that it was generally transforming into parametric solutions which are (apparently) more useful according to the CAS author for lots of advanced stuff. I know he made some changes there so if/when there is another version on the Prime firmware it would contain those improvements too which I think will be much more to your liking.

----------------------
TW

Although I work for the HP calculator group, the views and opinions I post here are my own.
Honor Student
Posts: 2
Member Since: ‎01-31-2016
Message 5 of 8 (138 Views)

Re: Differential Equations on HP Prime

Don't understand how to solve this differerntial equation on my HP Prime, Help please!

y'+2y=0  (0, -3)

 

Associate Professor
Posts: 1,638
Member Since: ‎02-17-2015
Message 6 of 8 (130 Views)

Re: Differential Equations on HP Prime

[ Edited ]

Hi!, Magqva:

 

Welcome, to Forum !.

 

The guides and manual ... http://support.hp.com/us-en/product/HP-Prime-Graphing-Calculator/5367459/model/5367460/manuals

 

You can solve, with CAS and Shift Home Settings, complex (a,b) ...

Screenshot_2016-01-31-17-54-35.png 

 

 

 

I am, a Volunteer here, not employed by HP.

Kind Regards.
Maké.
Honor Student
Posts: 2
Member Since: ‎01-31-2016
Message 7 of 8 (106 Views)

Re: Differential Equations on HP Prime

Thank's Make,

 

Yes i have been there in the manual and tryed to figure out how to press the different buttons but could not make it work. Tryed a lot but so far only different error message.

 

Any suggestions?

 

Magnus

Associate Professor
Posts: 1,638
Member Since: ‎02-17-2015
Message 8 of 8 (95 Views)

Re: Differential Equations on HP Prime

Hi!, Magqva:

 

See, the images ...

 

Screenshot_2016-02-01-10-41-06.png

 

Screenshot_2016-02-01-10-41-30.png

 

Screenshot_2016-02-01-10-40-47.png

 

Screenshot_2016-02-01-10-41-48.png

 

I am, a Volunteer here, not employed by HP.

Kind Regards.
Maké.
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