Posts: 43
Member Since: ‎09-29-2012
Message 1 of 4 (1,876 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]




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.



Posts: 43
Member Since: ‎09-29-2012
Message 2 of 4 (1,834 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 4 (852 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: 228
Member Since: ‎01-08-2009
Message 4 of 4 (818 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.


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