HP 48g Graphing Calculator - Manual (Page 210)

The message is based on the value of ihe equation —the difference
between the left and right sides of an equation, or the value returned
by an expression or program.
If a root is found, the SOLVE application returns a message describing
the root:
Zero The SOLVE application found a point where the
value of the equation is
0
within the calculator’s
12
-digit precision.
S i y n R e v e r s a l The SOIVE application found two points where
the value of the equation has opposite signs, but
it cannot find a point in between where the value
is 0. This may be because:
■ The two points are neighbors (they differ by 1
in the
12
th digit).
■ The equation is not real-valued between the
18 two points. The SOLVE application returns
the point where the value is closer to 0. If
the value of the equation is a continuous real
function, this point is the SOLVE application’s
best approximation of an actual root.
remjn One of the following occurred:
m The SOLVE application found a point where
the value of the equation approximates a local
minimum (for positive values) or maximum (for
negative values). The point may or may not
represent a root.
■ The SOLVE application stopped searching at
±9.9999999999915499, the largest or smallest
numbers in the calculator’s range of numbers.
To obtain more information about the solution:
■ Do any or all of the following:
n Move the highlight to the EQ field and press E x p R = (ENTER). For
an expression or program, the closer the result (labeled E::-ipr:) is
to 0, or for an equation, the closer the two results (labeled L e t t s
a n d R i g h t s ) are to each other, the more likely it is that the
SOLVE application found a root. You must use judgement in
considering the results.
18-4 Solving Equations