Quadratic Functions; Drawing A Quadratic Graph - Casio fx-9860GII Instructions Manual

The GDC solves the equations by an inverse matrix method.
In this example there is an error because the matrix is singular,
which means that there will be no unique solution.
To fi nd the solution you can use the reduced row echelon form
method instead.
Press MENU 1 .
Press OPTN | F2 MAT |
EXIT F4
Press EXIT | MATH |
Choose m as 3 and n as 4 and press
Type the coeffi cients from the three equations into the matrix,
pressing after each number.
EXE
Press .
The reduced row echelon form gives the solutions
to the equations of the line if the fi nal row of the
matrix is all zeroes.
There are no solutions and the fi nal row is not all zeroes.
In this example the equations are inconsistent.

Quadratic functions

1.6 Drawing a quadratic graph

Example 8
Draw the graph of y = x
Press MENU and choose 5: GRAPH and press
The default graph type is Function, so the form Y= is displayed.
Type y = x 2 − 2x + 3 and press
SHIF T F3
Press V-Window and choose
which are −10 ≤ x ≤ 10 and −10 ≤ y ≤ 10.
EXE F6
Press and DRAW.
The calculator displays the curve with the default axes.
© Oxford University Press 2012: this may be reproduced for class use solely for the purchaser's institute
F5
F6 | Rref
F1
MAT | F3 m × n
EXE
.
2 − 2x + 3 and display it using suitable axes.
EXE
EXE .
F3
STD to use the default axes
.
Casio fx-9860GII
If the calculator
displays a graph,
EXIT
press to return
to this screen.
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Continued on next page
Using a graphic display calculator 9