HP 9g - Page 77

E-77
(2) A = 3 , D = 2, N = 12 S (N) = S (12) = 168
[ ] ( 5 Seconds )
2 [ ] 3 [ ]
2 [ ] 12
[ ]
Example 57
 Create a program to generate a common ratio sequence ( A : First item,
R : common ratio, N : number )
Sum : S ( N ) = A + AR + AR
2
+ AR
3
....
1) R
1
2) R = 1
A ( N ) = AR
( N – 1 )
Nth item : A ( N ) = A
( N – 1 )