Texas Instruments PLUS TI-89 - Manual (Page 358)

Chapter 19: Numeric Solver 341
19SOLVER.DOC TI-89/TI-92 Plus: Numeric Solver (English) Susan Gullord Revised: 02/23/01 1:16 PM Printed: 02/23/01 2:19 PM Page 341 of 10
To use the graph cursor to select an initial guess:
1. Move the cursor (either free-moving or trace) to the point that
you want to use as the new guess.
2. Use 2 a to make the
Numeric Solver screen
active.
3. Make sure the cursor is on
the unknown variable, and
press †.
4. Press „ to re-solve the
equation.
From the split screen:
¦ To display the Numeric Solver full screen, use 2 a to make
the solver screen active, press …, and then select
2:Clear Graph
View .
– or –
¦ To display the Home screen, press 2 K twice.
When you solve an equation, its variables still exist after you leave
the Numeric Solver. If the equation contains single-character
variables, their values may inadvertently affect later symbolic
calculations. Before leaving the Numeric Solver, you may want to:
1. Press:
TI - 89: 2 ˆ
TI - 92 Plus: ˆ
to clear all single-character variables in the current folder.
2. Press ¸ to confirm the action.
The screen returns to the solver’s eqn: line.
Selecting a New
Initial Guess from
the Graph
Note: Cursor coordinate xc
is the unknown variable
value, and yc is the left
ì rt
value.
Returning to a Full
Screen
Clearing Variables
Before Leaving the
Numeric Solver
Tip: Any time you want to
clear single-character
variables listed in the solver,
use:
TI
- 89: 2 ˆ
TI - 92 Plus: ˆ
† sets the graph cursor’s xc value
as an initial guess and the yc value
as left
ì rt. The graph’s xmin and
xmax values are set as the bounds.