HP HP-18C User Manual

When you press [ INPUT lor 1fiIItI, the HP-18C displays:
VERIFYING FORMULA ...
to indicate that the solver is checking the formula. If the formula can-
not be interpreted, the HP-18C briefly displays:
I t~VAL I D FORt1ULA
and the cursor is positioned before the first character the solver could
not interpret. Check to be sure you've made no typing mistakes, and
that you've followed the rules for writing formulas on pages 141
through 143.
Calculations With Custom Menus
Pressing IfiIItI displays the custom menu for the current formula . If
the formula contains more than six user-variables, the solver creates
the label IIiIiJa to switch between sets of menu labels.
Figure 9·4. A Custom Menu
Q
i PPSyxLxW+9=COST
0.00
1DiI .. 1lDl1HU 4
Current formula (first 22 characters)
Custom menu
To do a calculation using a custom menu:
1. Store a value in all but one of the user-variables. For example, in
using the menu in figure 9-4, you can store values in PPSY, L,
and W to calculate COST. Or, you can store values in PPSY, W,
and COST to calculate L. To store a value, key in the number
and press the appropriate menu key. For example, 22.50 am
stores the value 22.50 in PPSY.
2. To start the calculation, press the menu key for the value you
want to calculate. If the solver is able to find a solution to the
formula, the answer is displayed on the calculator line.
9: The Formula Solver 131

HP HP-18C Specifications

General

Brand	HP
Model	HP-18C
Category	PDA
Language	English