12
07
Summing Geometric Progressions
1. The sum up to the th term of the geometric progression with first term and ratio
term may be calculated:
Program
?→ A:?→ B:?→ C:A(1- B ^ C)÷(1- B)→ D:D < 30 STEP >
OUTPUT D: sum of geometric progression
Execution Example:
Calculate the sum up to the 5th term of the geometric progression with first term 1 and ratio
term 3.
1+3+9+27+81=121
CA
B
AB
k 1–
k 1=
C
∑
AABAB
2
…
AB
C 1–
++ ++=
A 1 B
n
–()
1 B–
------------------------=
ON
MODE MODE MODE
1
PRGM
MODE
1
COMP
1
P1
Prog
1
S A
D R
P1
P2 P3 P4
G
1
EXE
S A
D R
P1
P2 P3 P4
G
3
EXE
S A
D R
P1
P2 P3 P4
G
5
EXE
S A
D R
P1
P2 P3 P4
G
関数電卓事例集 .book 12 ページ 2002年9月2日 月曜日 午後6時51分