http://www.ck12.org Chapter 12. Discrete Math
12.2 Arithmetic and Geometric Sequences
Here you will identify different types of sequences and use sequences to make predictions.
A sequence is a list of numbers with a common pattern. The common pattern in an arithmetic sequence is that
the same number is added or subtracted to each number to produce the next number. The common pattern in a
geometric sequence is that the same number is multiplied or divided to each number to produce the next number.
Are all sequences arithmetic or geometric?
Watch This
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/62261
http://www.youtube.com/watch?v=jExpsJTu9o8 James Sousa: Arithmetic Sequences
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/62263
http://www.youtube.com/watch?v=XHyeLKZYb2w James Sousa: Geometric Sequences
Guidance
A sequence is just a list of numbers separated by commas. A sequence can be finite or infinite. If the sequence is
infinite, the first few terms are followed by an ellipsis(...)indicating that the pattern continues forever.
An infinite sequence: 1, 2 , 3 , 4 , 5 ,...
A finite sequence: 2 , 4 , 6 , 8
In general, you describe a sequence with subscripts that are used to index the terms. Thekthterm in the sequence is
ak.
a 1 ,a 2 ,a 3 ,a 4 ,...,ak,...
Arithmetic sequences are defined by an initial valuea 1 and a common differenced.