HP 49g Graphing Calculator - Manual (Page 113)

Numeric option
When the Numeric option is set, the calculator returns only numeric
solutions to calculations. Otherwise, the calculator returns symbolic
solutions.
With the numeric option set, any variables that a calculation contains
must exist in the current path, and contain a numeric value. If this is not
the case, the calculator retmns an error. Any constants with an
approximate numeric value, such as n, are evaluated and the approximate
value substituted into the calculation.
For example, consider the calculation SIN{2* tc * x + 3*7i*X)
® If the Niuneric option is set, and a numeric value for X is stored in the
current path, the calculator returns the approximate answer, accurate
to 12 decimal places. That is, it substitutes the niuneric value for X and
the approximate value for 7t into the equation.
• If the Numeric option is set and there is no numeric value for X stored
in the ciuxent path, the calculator retiuns an eiTor.
• If tire Numeric option is clear, and no value for X is stored in the
cun'ent path, the calculator simplifies the expression and returns
SIN(5 .X.Tl) .
Approx option
The Approx option setting detennines how the HP 49G expresses answers
to calculations;
• When the Approx option is clear, the HP 49G finds exact solutions to
calculations where possible. That is, it expresses the solution as an
irreducible expression containing exact terms.
® Wlren the Approx option is set, the HP 49G expresses solutions to
12-digit accuracy.
Note that you can change the setting of the Approx option by using the
CAS Modes input form or by pressing simultaneously 0 and (I
n TER).
• If the calculator is in exact mode, pressing 0 (E n T0 changes to
approximate mode.
• If the calculator is in approximate mode, pressing 0(EÑT0 changes the
setting to exact mode.
Working with expressions Page 5-3