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Is there a way to have the solver of an HP49G work similar to that of the HP48SX. I mean removing the menus and having working using the function buttons at the bottom of the screen.

My problem is that my results are long numbers that do not fit in the default variable fields of the HP 49G.

Also, in the HP49G where are the undo and the last stack funtions of the HP 48SX?

Thanks

Edited: 20 Jan 2004, 10:05 a.m.

Q:"Is there a way to have the solver of an HP49G work similar to that of the HP48SX. I mean removing the menus and having working using the function buttons at the bottom of the screen.



A: [RS]&[ 7 ] eg. NUM.SLV. but hold the shift key. Then select |ROOT| by pressing [F1]. Key in your Equation and press [LS]|EQ| (equal to 'EQ' STO). Again press [F1], which says |SOLVR| above it. There you are!



Q: "My problem is that my results are long numbers that do not fit in the default variable fields of the HP 49G."



A: Use: 2 FIX



Q: "Also, in the HP49G where are the undo and the last stack funtions of the HP 48SX?"



A: [RS][HIST] (says UNDO above it in red text). [LS][ENTER] (says ANS above it, which is the LASTARG eg. LAST)

[VPN]

[RS] & 7 = menu. Then I select option [1] and get the HP Eq. Solver.

Is there a way to run the EQ. Solver without the variable menu. Say in a way similar to the HP 49S?

The reason are:

1) I think it runs faster
2) I get to see the iteration results in the upper right hand corner of the screen. So if it is going out of range I can stop it by hand.

Thanks in advance.

Felix

Felix --

Try ROOT, e.g.,

RAD
'10*exp(-x)-sin(x)'
'x'
6.5 (guess)
ROOT

Answer of 6.30152 is returned in "radians" angular mode.

This is a follow-up to an answer I posted to Felix' question about how to utilize the root-finding solver on the 49G using only stack arguments, not menus.

My answer:

Felix --

Try ROOT, e.g.,

RAD
'10*exp(-x)-sin(x)'
'x'
6.5 (guess)
ROOT

Answer of 6.30152 is returned in "radians" angular mode.


I subsequently discovered that the root-finding algorithm on the RPL 48/49 machines ("ROOT") works like the one on the RPN machines ("SOLVE/SOLVER"). Also, ROOT is similar to SOLVE on the 32S/ii and 42S in that the first guess is to be loaded into the variable to be solved for, while the second guess is put onto the stack.

On earlier RPN machines, the variable to be solved is taken from the x-register at the beginning of the function, so both initial guesses are put onto the stack in the x- and y-registers.

ROOT seems to have lost one refinement from SOLVE -- if no root is found in SOLVE, an error message is given. However, if no root is found by ROOT, it just blithely returns the closest answer it could find, without any message. (Is there a "solve failed" flag I don't know about?

The equation I gave has the following points of interest:

     x               f(x)         remark
0.00 10.00
2.51399621560 0.22224030507 local min
4.61300597767 1.09428505564 local max
6.30152146492 0 first root

On all units, guess-pairs to the left of the local max will cause ROOT/SOLVE to stop at the local min. The 15C gives "Error 8"; the 41C Advantage gives "NO"; the 32Sii gives "NO ROOT FND"; the 42S says "Extremum".

ROOT on the 28C/48G/49G give no such disclaimers.

ROOT/SOLVE tend to find the first root with guesses to the right of the local max, although ROOT is more likely to find higher roots with guesses near the flat area around the local max.

Any insights?

A little late, I would give you a way to solve equations in the HP49 using the soft keys. This is more practical as the display is free for intermediate calcualtions and results are diplayed in the set format.

1. Store the equation in 'EQ':
...your equation... 1 'EQ' STO.

2. Select the solver menu:
30 MENU

If you use the solver often it is very convenient to put the following small program inb the Home directory:
<<'EQ' STO 30 MENU>>

If you call it SOL, as an example the program to calculate the impedance of a capacitor or an inductor would look like this:
<< {'X=1/(2*PI*C*F)' 'X=2*PI*C*F'} SOL>> (where PI is the pi simbol).

como utilizar la intstruccion "RKFStep"