HP 48g Graphing Calculator - Manual (Page 211)

D Plot the expression or equation in the region of the answer. The
PLOT application will show any local minimum, maximum, or
discontinuity.
□ Check the system flags that detect mathematical errors (see
appendix B for a list of such errors). For example, flag —25
indicates whether overflow occurred.
If the SOLVE application can’t return a result, it displays a message
indicating the reason;
E'-ad
Guess
One or more of the initial guesses lie outside
the domain of the equation—or units for the
unknown variable aren’t consistent with the units
for the other variables. Therefore, when the
equation was evaluated, it didn’t return a real
number or it generated an error.
The value of the equation is the same value at
every point sampled.
18
Solving Options
To display the root-finder at work:
1. Immediately after pressing S O L V E to begin the root-finder, press
( enter ). You will see two intermediate guesses and the sign of the
expression evaluated at each guess (displayed to the left of each
•“! j Q •"! 0 eh ; 1“ se ; ^ ^
■ I" ~"1 « 3 1 1 1 1 1 1 1 1 4 9
Watching the intermediate guesses can give you information about
the root-finder’s progress—whether the root-finder has found a sign
reversal (the guesses have opposite signs), or if it is converging on a
local minimum or maximum (the guesses have the same signs), or if
it is not converging at all. In the latter case, you may want to halt
the root-finder and restart with a new guess.
To halt and restart the root-finder:
1. While the root-finder is working, press
( C A N C E L
|. The root-finder
halts and displays current guess in the unknown variable’s field.
2. To restart the root-finder, do one of the following:
Solving Equations 18-5