Texas Instruments TI-86 - Manual (Page 215)

Chapter 15: Equation Solving
203
15EQSOLV.DOC TI-86, Chap 15, US English Bob Fedorisko Revised: 02/13/01 2:34 PM Printed: 02/13/01 3:04 PM Page 203 of 12 15EQSOLV.DOC TI-86, Chap 15, US English Bob Fedorisko Revised: 02/13/01 2:34 PM Printed: 02/13/01 3:04 PM Page 203 of 12
Entering an Equation in the Equation-Entry Editor
The equation solver uses two editors: the equation-entry editor, where you enter and edit the
equation you want to solve, and the interactive-solver editor, where you enter known variable
values, select the variable for which you want to solve, and display the solution.
To display the equation-entry editor, press - t. In
this editor, you can:
♦
Enter an equation directly.
♦
Enter a defined equation variable’s individual
characters or select it from the
VARS EQU menu.
♦
Recall the contents of a defined equation variable.
As you enter or edit the equation, the TI -86 automatically stores it to the variable eqn .
The VARS EQU menu is a menu version of the VARS EQU screen (Chapter 2). The items are
all variables to which an equation is stored. This includes all selected and deselected
equation variables defined in the equation editors of all four graphing modes (Chapters 5, 8,
9, and 10). The menu items are in alphanumeric order.
♦
If you select an equation variable from the menu, the variable is pasted to the cursor
location, overwriting characters for the length of the variable name.
♦
If you press - –, select an equation variable from the menu, and then press b,
the variable contents are inserted at the cursor location.
If you enter an equation variable, the TI -86 automatically converts it to the equation
exp= equationVariable . If you enter an expression directly, the TI -86 automatically converts
the expression to the equation exp= expression .
The equation can have more
than one variable to the left of
the equal sign, as in
A+B=C+sin D
.
You can display other menus
in the equation-entry editor.
An ellipsis (...) indicates that
an entered equation
continues beyond the screen.
To move directly to the start
of the equation, press
- ! ;
to move directly to the end,
press
- " .