HP 39GS hp 39gs_user's guide_English_E_HDPMG39AE13.pdf - Page 90

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 Zero Sign Reversal Extremum Condition The Solve aplet 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. 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. 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. 7-6 Solve aplet