How to compute the value of symbolic expressions in HP-50g?



#4

I realize this must be a very simple question, but how do I evaluate expressions containing symbols?
Suppose you have a simple expression, for instance:

X*(M-1)
-------
X*(M+1)
I would like to press on a key that did:
  • Prompts for all the values of the symbols, such as X, M in the example, showing the previous value if any.
  • Returns the value of the expression.
This seems to be rather basic functionality, similar to the equation mode, so I am sure that there is a way to do it... but which way?
Many thanks... as you can see, I am a beginner with my 50g.

Luca


#5

No problem, Luca,

Just use the equation solver thusly:

Assuming your equation is on the stack level 1:

...copy it (up arrow and put the pointer on level 1, right shift, copy, enter)

...open the equation solver (right shift, num.slv, option 1 (which is Solve equation).

...with the Eq field highlighted, hit paste (right shift, paste) and enter. (note; if your equation is stored in a variable, just hit CHOOSE and navigate to your variable)

...The application will put the equation into the field, and it's variables will appear below. Select any variable and put a value into it (by keying in the number and hitting enter). Highlight the variable you want to solve for and hit solve (f6 softkey). You can put an initial guess into the variable you want to solve for prior to solving if you want to. You can change the values and or solve for any of the variables you want to.

...note that when you exit the solver application, the solution(s) found by the equation solver have automatically been put on the stack as a tagged object(s), which can then be used in subsequent calculations.

best regards,

hal


#6

Thanks! This helps.

I just wish that the numeric solver would display the value it computes when I assign values to the variables and press EXPR= , rather than just leaving the value on the stack.

I did not know I had to use the solver even for evaluating an expression, but I see that it works well. Thanks!

Luca


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP Prime suggestion to avoid Numeric/Symbolic confusion Chris Pem10 4 954 11-19-2013, 05:49 AM
Last Post: bluesun08
  HP Prime - Saved formulas, expressions CR Haeger 6 1,049 10-07-2013, 08:25 PM
Last Post: CR Haeger
  HP-Prime: issues in entering expressions fhub 30 3,463 10-02-2013, 12:32 AM
Last Post: Tim Wessman
  Product Series and Limit Expressions on the 50G Matt Agajanian 13 1,858 09-03-2013, 02:02 PM
Last Post: Simone Cerica
  [HP-Prime] AMBIGUITY between Numerical Calculation (HOME) and Numerical/Symbolic Calculation (CAS mode) CompSystems 2 705 08-18-2013, 07:06 PM
Last Post: CompSystems
  HP 50g Takes hours to compute a convergent series Matthew Richards 10 1,487 05-14-2013, 03:30 PM
Last Post: Thomas Klemm
  OT: Google evaluates mathematic expressions (with a twist) DavidShenk 4 913 02-13-2013, 09:05 AM
Last Post: Juan J
  Symbolic limit of a function of 2 variables, HP49/50 Gilles Carpentier 0 417 08-26-2012, 10:28 AM
Last Post: Gilles Carpentier
  Immediate algebraic expressions in RPL+ Oliver Unter Ecker 8 1,144 11-19-2011, 04:29 AM
Last Post: Oliver Unter Ecker
  HP 50g trilogy. The new HP 50g Blue (and II) Pablo P (Spain) 18 2,449 09-19-2011, 03:08 AM
Last Post: BruceH

Forum Jump: