Solving A System Of Nonlinear Equations - TI -82 Manual Book

Solving a System of Nonlinear Equations

Solve the equation X
system of two equations and two unknowns: Y=X
ZOOM factors to control the decimal places displayed on the graph.
Procedure
1. Press z. Select the default
and turn off all stat plots. Press o. Turn off all functions and enter the
functions
2. Press q and select
areas that might contain solutions (points where the two functions
appear to intersect).
3. Press q ~ and select
Set XFact=10
4. Press q
free-moving cursor on the apparent intersection of the functions on the
right side of the display. As you move the cursor, note that the
coordinates have one decimal place.
5. Press Í to zoom in. Move the cursor over the intersection. As you
move the cursor, note that now the
decimal places.
6. Press Í to zoom in again. Move the free-moving cursor to a point
exactly on the intersection. Note the number of decimal places.
7. Press y ã
First curve
near the intersection and press Í. What are the coordinates of the
intersection?
8. Press q and select
9. Press q. Select
intersection.
3
–2X=2cosX graphically. Stated another way, solve the
3
and
Y =X –2X Y =2cos X
7 8
ZDecimal
SetFactors...
and YFact=10 .
2 (to select Zoom In
ä and select
CALC
and Í to select the
ZDecimal
Zoom In
3
–2X and Y=2cosX. Use the
settings. Press y [
MODE
.
. The display shows that there are two
from the
). Use ~, |, }, and † to position the
X and Y coordinates have two
. Press Í to select the
intersect
Second curve
to redisplay the original graph.
and explore as above the other apparent
STAT PLOT
ZOOM MEMORY
X and
. Now trace to a Guess
Applications 14-7
]
menu.
Y