More Complicated Functions; Solving A Combined Quadratic And Exponential Equation - Casio fx-9860GII Instructions Manual

More complicated functions

1.20 Solving a combined quadratic
and exponential equation
To solve the equation, fi nd the point
of intersection between the quadratic
function y = x
2
− 2x + 3 and the
1
exponential function
y = 3 × 2
−x + 3.
2
Example 23
Solve the equation x 2 − 2x + 3 = 3.2
MENU
Press and choose 5: GRAPH and press
The default graph type is Function, so the form Y= is displayed.
2
Type x − 2x + 3 in Y
1
Then type 3 × 2
−x
+ 4 in Y
SHIF T F3
Press V-Window and choose
use the default axes which are −10 ≤ x ≤ 10
and −10 ≤ y ≤ 10.
Press EXE and F6 DRAW.
The calculator displays the curves with the default axes.
Adjust the window to make the quadratic curve fi t the screen better.
F5 F5
Press G-Solv and
The calculator displays the intersection of the two
straight lines at the point (2.58, 4.50).
The solutions are x = 2.58 and y = 4.50.
© Oxford University Press 2012: this may be reproduced for class use solely for the purchaser's institute
−x + 4.
EXE
EXE
and press .
EXE
and press .
2
F3
STD to
ISCT.
.
(–)
2
Note: Type
X,i,T
to enter 2 –x .
The returns you to
the baseline from the
exponent.
Casio fx-9860GII
Using a graphic display calculator 24