Texas Instruments PLUS TI-89 - Manual (Page 356)

Chapter 19: Numeric Solver 339
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 339 of 10
With all known variables
defined:
1. Move the cursor to the
unknown variable.
2. Press „ Solve .
A é marks the solution and
left ì rt . The é disappears
when you edit a value,
move the cursor to the
equation, or leave the
solver.
Using the solution and your entered values, the left and right sides of
the equation are evaluated separately.
left ì rt shows the difference,
which indicates the solution’s accuracy. The smaller the value, the
more accurate the solution. If the solution is precise,
left N rt=0 .
If you: Do this:
Want to solve for other
values Edit the equation or variable values.
Want to find a different
solution for an equation
with multiple solutions Enter an initial guess and/or a new set of
bounds close to the other solution.
See the message: Press N. The unknown variable shows
the value being tested when the error
occurred.
¦ The left ì rt value may be small enough
for you to accept the result.
¦ If not, enter a different set of bounds.
Solving for the Unknown Variable
After you type an equation in the Numeric Solver and enter
values for the known variables, you are ready to solve for the
unknown variable.
Finding the Solution
Note: To stop (break) a
calculation, press
´ . The
unknown variable shows the
value being tested when the
break occurred.
Note: An iterative process is
used to solve an equation. If
the iterative process cannot
converge on a solution, this
error occurs.
Put the cursor on the variable
you want to solve for.