HP 39gII, User Manual

Page: 76 / 355

66 Solve app
Interpreting results
After Solve has returned a solution, press in the
Numeric view for more information. You will see one of
the following three messages. Press to clear the
message.
Message Condition
Zero
The Solve app found a point where
both sides of the equation were
equal, or where the expression was
zero (a root), within the calculator's
12-digit accuracy.
Sign
Reversal
Solve found two points where the
difference between the two sides of
the equation has opposite signs, but
it cannot find a point in between
where the value is zero. Similarly,
for an expression, where the value
of the expression has different signs
but is not precisely zero. This might
be because either the two points are
neighbours (they differ by one in the
twelfth digit), or the equation is not
real-valued between the two points.
Solve returns the point where the
value or difference is closer to zero.
If the equation or expression is
continuously real, this point is
Solve’s best approximation of an
actual solution.
Extremum
Solve found a point where the value
of the expression approximates a
local minimum (for positive values)
or maximum (for negative values).
This point may or may not be a
solution.
Or: Solve stopped searching at
9.99999999999E499, the largest
number the calculator can
represent.
Note that the value returned is
probably not valid.