HP-PRIME CAS SOLVING

[fabrice48]

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 ????

[Helge Gabert]

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!)).

[fabrice48]

it's very strange, i do the same as you but my machine answer this :
{}
have you an idea ?

[fabrice48]

i know why :

teh rule seems in CAS only lower cas character allowed.

[Helge Gabert]

Yes!

[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). ????

[Han]

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)

[Helge Gabert]

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?

[Han]

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.