Casio fx-9860GII User Manual

Using a graphic display calculator
© Oxford University Press 2012: this may be reproduced for class use solely for the purchaser’s institute
Casio fx-9860GII
Sequences and series
1.21 Summation of a series
Example 24
Find the sum of the fi rst 20 terms of the arithmetic sequence 4, 7, 10, 13, …
The kth term of an arithmetic sequence is u
k
= u
1
+ (k − 1)d
In this example u
1
= 4, d = 3 and n = 20.

å
n
k
Sk
20
1
4( 1)3
Press
MENU
. You will see the dialog box as shown on the right.
Choose 1: RUN·MAT and press
EXE
.
Press
F4
MATH |
F6
|
F2
Σ(
The template matches the written Sigma formula.
Enter the variables, values and the function as they are written.
Use the
keys to move around the template.
The sum of the terms of the sequence is 650.
Example 25
Find the sum of the fi rst 12 terms of the geometric sequence
31
1
3
1
9
, , , , ...−−
The kth term of a geometric sequence is u
k
= u
1
⋅ r
k −1
In the example u
1
= 3,
r =−
1
3
and n = 12.
1
12
1
1
3
3
k
n
k
S


å
æö
÷
ç
÷
ç
÷
ç
èø
Press
MENU
. You will see the dialog box as shown on the right.
Choose 1: RUN·MAT and press
EXE
.
Press
F4
MATH |
F6
|
F2
Σ(
The template matches the written Sigma formula.
Enter the variables, values and the function as they are written.
Use the
keys to move around the template.
The sum of the terms of sequence is 2.25, to 3 signifi cant fi gures.
25

Casio fx-9860GII Specifications

General

Type	Graphing
Form factor	Desktop
Control type	Buttons
Product color	Silver
Housing material	Plastic
Built-in capability	Yes
Digits	- digits
Display type	LCD
Second display	No
Display tilting	-
Display resolution	64 x 128 pixels
Display character size	8 x 21 mm
Display number of lines	8 lines
Display number of characters	21
Flash memory	1.5 MB
RAM capacity	0.064 MB
Storage media type	Flash
Battery type	AAA
Power source	Battery
Number of batteries supported	4