Sequences

6 flashcards · Mathematics · by Nelly S

1. How to find the next term of an arithmetic sequence?

   un = a+(n-1)d

2. How to find the sum of terms in an arithmetic sequence without knowing the last term?

   Sn = n/2(2a+(n−1)d)n/2 (2a +(n - 1)d)n/2(2a+(n−1)d)

3. How to find the sum of terms in an arithmetic sequence knowing the last term?

   Sn= n/2(a+l)n/2 (a+l)n/2(a+l)

4. How to find the next term of a geometric sequence?

   un = arn-1

5. How to find the sum of terms in a geometric sequence?

   Sn = a(rn−1)/r−1a(r^n-1)/r-1a(rn−1)/r−1

6. What is the sum to infinity of a geometric sequence?

   S∞ = a/1−ra/1-ra/1−r