Chapter 1: Sequences

Question 1

what is the formula to determine an arithmetic sequence

Answer 1

tn = t1 + (n - 1) d

Question 2

what is the formula to determine an arithmetic series

Answer 2

Sn = n/2 (t1 + tn)

Sn = n/2 (2t1 + (n - 1) d)

Question 3

what is the formula to determine a geometric sequence

Answer 3

tn = t1 * r^n-1

(its r square n - 1)

Question 4

what is the formula to determine a geometric series

Answer 4

Sn = t1 (r^n - 1) / r - 1

(its r squared n and then minus 1, the r and 1 are on the same level)

Sn = rtn - t1 / r - 1

Question 5

what is the formula to determine an infinite geometric series

Answer 5

S∞ = t1 / 1 - r