HP 49g Graphing Calculator - Manual (Page 134)

After it solves an equation, the muueric solver returns infonuation relating
to the solution process.
To display the solution information, press
info
.
If the numeric solver
found a solution to the equation, it displays one of the following three
messages:
Zei'o The numeric solver was able to solve the equation within
the limits of its accuracy.
Sign Reversal The numeric solver formd two points where the value of
the equation has opposite signs, but it camrot find a point
in between where the value is 0. Possible causes are that
the two points are less than one in the 12th decimal place
apart, or the equation is not real-valued between the sign
reversal points.
Extremum This represents one of the following conditions:
® The numeric solver foimd a point where the value of
the equation approximates a local minimum or
maximum. The point may or may not represent a root.
® The numeric solver stopped searching at either the
largest or smallest number in the calculator’s range.
If the nmueric solver did not find a solution, it displays one of the
following explanatory messages:
Bad Guess(es) One or more of the initial guesses lie outside the domain
of the equation.
Constant? The value of the equation is the same at every point that
was sampled.
Interpreting results
Page 6-4 Solving equations