Page 14 - DIGITAL BOOK MUHAMMAD AZWARDI NASUTION

If between U and U be inserted k number. So
1
2

forms arithmatic sequence with common difference

b’. Find the formula b’

U 1 = a

U 2 = a + b

new U 2 =U k + 2

k
a
+ b = a + ( + 2 − ) 1 ' b

k
b
= ( + ) 1 ' b

b

b '=
( + ) 1
k