Graphing Polynomials And Tracing To Find The Roots - Sharp EL9600C - Graphing Calculator Handbook

Graphing Polynomials and Tracing to Find the Roots

A polynomial y = f (x) is an expression of the sums of several terms that contain different
powers of the same originals. The roots are found at the intersection of the x-axis and
the graph i. e., when y = 0.
Example
Draw a graph of a polynomial and approximate the roots by using zoom-in and
Trace features.
1.
Graph the polynomial y = x
2.
Approximate the left-hand root.
3.
Approximate the middle root.
4.
Approximate the right-hand root.
There may be differences in the results of calculations and graph plotting depending on the setting.
Before
Return all settings to the default value or to delete all data.
Start
Set the zoom to the decimal window:
Setting the zoom factors to 5 :
As Substitution feature is only available on the EL-9600, this section does not apply to the EL-9400.
Step & Key Operation
*Use either pen touch or cursor to operate.
1
1
Enter the polynomial
-
3 2
y = x - 3x + x + 1.
Y=
EZ
5
ENTER ENTER
* *
1
2
- Enter the coefficients.
2nd F SUB
-
1 ( )
ENTER
*
1 1
ENTER
*
1
3
- Return to the equation display
screen.
2nd F EXE
1
4
View the graph.
-
GRAPH
3 2
- 3x + x + 1.
A
ZOOM
B
ZOOM ENTER
*
ENTER
* *
3
ENTER
*
ENTER
EL-9600 Graphing Calculator
( )
7
ENTER ALPHA
* * *
5 5
ENTER ENTER 2nd F QUIT
Display
It may take few seconds for
the graph to be drawn.
Enter each coefficients when
the cursor is displayed.
Notes
4-1