sparknotes
Sequences and Series
Problems
Problem : Define the arithmetic sequence a 1 = 6 ; a n+1 = a n - 2 explicitly.
Problem : What is the sum of the first six terms of the sequence a n = 2n + 6 ?
Problem : What is the sum of the first 45 terms in the arithmetic sequence a 1 = 3 ; a n+1 = a n + 5 ?


(a
1 + a
6) = 3(8 + 18) = 78
(45d - d )= 135 + (22.5)(220) = 5085


