HP 50g Graphing Calculator - Manual (Page 792)

Page 27-10
6. Press !MSOLV! to launch the solver with the new set of equations.
To change the title and menu for a set of equations
1. Make sure that the set of equations is the current set (as they are used when
the Multiple-Equation Solver is launched).
2. Enter a text string containing the new title onto the stack.
3. Enter a list containing the variable names in the order you want them to
appear on the menu. Use a "" to insert a blank label. You must include all
variables in the original menu and no others, and you must match
uppercase and lowercase characters.
4. Press G—` EQLIB EQLIB $MES# !MINIT!.
Interpreting results from the Multiple-Equation Solver
The Multiple-Equation Solver solves for variables by repeatedly looking through
the set of equations for one that contains only one variable that’s unknown (not
user-defined and not found by the solver during this solution). It then uses the
root-finder to find that value. It continues eliminating unknown variables until it
solves for the variable you specified (or until it can’t solve for any more
variables). Each time the Multiple-Equation Solver starts solving for a variable,
only the variables with black menu labels are known.
During the solution process, the Multiple-Equation Solver shows the variable it is
currently solving for. It also shows the type of root found (zero, sign-reversal, or
extremum) or the problem if no root is found (bad guesses or constant).
The following messages indicate errors in the problem setup:
Bad Guess(es). Units may be missing or inconsistent for a variable.
For a list of guesses, at least one of the list elements must have consistent
units.
Too Many Unknowns. The solver eventually encountered only
equations having at least two unknowns. Either enter other known values,
or change the set of equations.