334 Chapter 19: Numeric Solver
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 334 of 10
Steps
³
TI-89
Keystrokes
›
TI-92 Plus
Keystrokes Display
1. Display the Numeric Solver. O9O9
2. Enter the equation.
When you press
¸
or
D
, the
screen lists the variables used in the
equation.
jAÁc
jM2|
jM1dec
jM2«
jM1dp
jG¸
AÁc
M2|
M1dec
M2«
M1dp
G¸
3. Enter values for each variable,
except the unknown variable
m1.
Define
m2
and
g
first. Then define
a
.
(You must define
g
before you can
define
a
in terms of
g.
) Accept the
default for
bound
. If a variable has
been defined previously, its value is
shown as a default.
D10DD
9.8CCC
jGe3
D10DD
9.8CCC
Ge3
4. Move the cursor to the unknown
variable m1.
Optionally, you can enter an initial
guess for
m1
. Even if you enter a
value for all variables, the Numeric
Solver solves for the variable marked
by the cursor.
DD DD
5. Solve for the unknown variable.
To check the solution’s accuracy, the
left and right sides of the equation are
evaluated separately. The difference
is shown as
leftìrt
. If the solution is
precise,
leftìrt=0
.
„„
6. Graph the solution using a
ZoomStd viewing window.
The graph is displayed in a split
screen. You can explore the graph by
tracing, zooming, etc.
…3…3
7. Return to the Numeric Solver
and exit the split screen.
You can press
¸
or
D
to
redisplay the list of variables.
2a
…2
2a
…2
Preview of the Numeric Solver
Consider the equation a=(m2ìm1)/(m2+m1)ùg, where the known values are m2=10 and
g=9.8. If you assume that a=1/3 g, find the value of m1.
g/3 is evaluated when you
move the cursor off the line.
é marks the calculated values.
The variable marked by the
cursor (unknown variable
m1) is on the x axis, and
leftìrt is on the y axis.