Basic Sequences
What does a1 mean?
The first term
What does d stand for?
The common difference.
How do we find r?
a2 ÷ a1
Find the first three terms of the sequence.
an= -1 + 6(n - 1)
-1, 5, 11
Find d of the following sequence.
870, 750, 630, 510
d = -120
Find r of the following series
2, 14, 98, 686
r = 7
Find the next three terms of the sequence
25, 34, 43, 52,...
61, 70, 79
Find the explicit formula for the following sequence.
14, 11, 8, ...
an= 14 - 3(n - 1)
Find r of the following series
8, 16, 32, 64,...
r = 2
Find a18 of the following sequence.
an = -3 - 8(n - 1)
-139
Find the 21st, 22nd, and 23rd term of the following sequence.
-10, -14, -18, -22
-90, -94, -98
Write the formula for the following geometric sequence.
375, 75, 15, 3, ...
Hint: a1(r)n-1
an= 375(1/5)n-1
What is a12 of this sequence?
5, 12, 19, 26,...
82
Find the explicit formula of the following sequence.
-4, 1, 6, 11, ...
an = -4 + 5(n - 1)
Write the explicit formula for the following geometric sequence.
7, -7, 7, -7, ...
Hint: a1(r)n-1
an= 7(-1)n-1