User vars

[CR Haeger]

Hello,

Yeah the HP Prime is "wonder"ful - as in I wonder how to use it

I have also been messing around with User vars, the solver and the spreadsheet. It is tricky setting up saved equations for use in the Solver, Function or other apps.

In your program, you may have problems defining solver equations like Electric.E1:='(W/E)=I'; as the variables W, E and I are predefined Home variables (with values). So if you then check, E1 in Electric solver, you may see 0=0 or undef=0 if E is zero.

If you used Electric.E1:=Watts/Volts=Amps; then these are "yet" to be defined user variables (Watts, Volts, Amps). Checking E1: should show Watts/Volts=Amps properly. However, when you initially go to the Num view, it will ask if you want to create these three user variables before it performs any numerical solving.

Note that you might also try creating a new "Electric" spreadsheet. In it you can define variables in cells, define equations that refer to these variables/cells and even use some cas commands, like solve() to perhaps perform numerical or symbolic solutions. You still need to be aware of what Home and User variables values (if any) are while using the spreadsheet...

I too, would like to know how to save useful formulas in symbolic form, then use them over and over in Home, Cas, Apps and/or programs. Maybe some experts can guide us.

Best,
Carl