The Museum of HP Calculators

HP Forum Archive 21

 HP-PRIME CAS SOLVINGMessage #1 Posted by fabrice48 on 19 Oct 2013, 11:55 a.m. I have an HP48 with it i solve some expression, but on HP-PRIME, i don't find how to do the same : example : i have the electrical : U=R*I i want to 'transform it' in CAS style, ON HP48 i do this : 'U=R*I' 'I' ISOL then the calculator answer : I=U/R How to do this on PRIME ????

 Re: HP-PRIME CAS SOLVINGMessage #2 Posted by Helge Gabert on 19 Oct 2013, 12:13 p.m.,in response to message #1 by fabrice48 Try solve(u=r*ii, ii) gives [ii=(1/r)*u] I used the CAS do to this, and ii (because i is allocated (complex!)).

 Re: HP-PRIME CAS SOLVINGMessage #3 Posted by fabrice48 on 19 Oct 2013, 12:19 p.m.,in response to message #2 by Helge Gabert it's very strange, i do the same as you but my machine answer this : {} have you an idea ?

 Re: HP-PRIME CAS SOLVINGMessage #4 Posted by fabrice48 on 19 Oct 2013, 12:22 p.m.,in response to message #3 by fabrice48 i know why : teh rule seems in CAS only lower cas character allowed.

 Re: HP-PRIME CAS SOLVINGMessage #5 Posted by Helge Gabert on 19 Oct 2013, 12:26 p.m.,in response to message #4 by fabrice48 Yes!

 Re: HP-PRIME CAS SOLVINGMessage #6 Posted by Helge Gabert on 19 Oct 2013, 12:38 p.m.,in response to message #5 by Helge Gabert Now I have a question. I'm running the same command again, from the CAS history, and my output is in a different format, in curly brackets and without the equal sign and the variable to solve for. {(1/r)*u} I didn't change any flag settings (that I'm aware of). ????

 Re: HP-PRIME CAS SOLVINGMessage #7 Posted by Han on 19 Oct 2013, 1:22 p.m.,in response to message #6 by Helge Gabert Quote: Now I have a question. I'm running the same command again, from the CAS history, and my output is in a different format, in curly brackets and without the equal sign and the variable to solve for. {(1/r)*u} I didn't change any flag settings (that I'm aware of). ???? I believe this is normal behavior (the HP Prime does not do everything in the same way as older calculators)

 Re: HP-PRIME CAS SOLVINGMessage #8 Posted by Helge Gabert on 19 Oct 2013, 1:35 p.m.,in response to message #7 by Han Yes, but when I first ran the command solve(u=r*ii, ii)on the Prime (CAS view) I got this: [ii=(1/r)*u] Now I get this on the exact same machine, with the same command solve(u=r*ii, ii), again in CAS view: {(1/r)*u} Strange. What output format do you get?

 Re: HP-PRIME CAS SOLVINGMessage #9 Posted by Han on 19 Oct 2013, 1:21 p.m.,in response to message #4 by fabrice48 Quote: i know why : teh rule seems in CAS only lower cas character allowed. The upper case single characters are actually built-in variables. Upper-case variables such as MYVAR is fine.

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