Sequences

Question 1

What is an arithmetic sequence?

Answer 1

• An arithmetic sequence is one which has a common difference.

Example:

2, 4, 6, 8, 10, 12, 14 (Common difference = 2)

12, 15, 18, 21, 24, 27 (Common difference = 3)

Question 2

What is a geometric sequence?

Answer 2

• A geometric sequence is one which has a common ratio.
• You multiply the current term by the common ratio to get the next term in the sequence.

Example:

2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 (Common ratio of 2)

Question 3

When dealing with sequences, what do the different variables in the formulae represent?

Answer 3

• a = first term
• d = common difference
• r = common ratio
• n = number of terms

Question 4

What are the 3 main categories in which a sequence can be classified?

Answer 4

• Convergent
• Divergent
• Varying (Between larger and smaller numbers)