Sequences

Given the sequence 2, 8, 14, 20, 26, ... What is the common difference?

• 2

• 4

• 6

• 8

What number follows 20 in this arithmetic sequence?

8,11, 14, 17, 20

• 5

• 23

• 26

• 29

Is the sequence geometric? If so, identify the common ratio.

6, 12, 24, 48

• yes, 2

• yes, -2

• yes, 4

• no

What is the fifth term of the geometric sequence?

5, 15, 45,...

• 135

• 1875

• 1215

• 405

Find the 8th term of a geometric sequence for which a1=2 and r = 7?

• 823,543

• 11,529,602

• 1,647,086

• 5,764,801

Define arithmetic sequences.

• A sequence whose terms change by adding the same number each time.

• A sequence whose terms change by multiplying the same number each time.

• A sequence whose terms change by dividing the same number each time.

• A list of numbers that often (but not always) form a pattern.

What does a₁ represent?

• Any term

• First term

• Last term

Identify a₁

97, 86, 75, 64, ...

• 64

• 11

• -11

• 97

Which formula is used to find the explicit equation for geometric sequences?

• a_n = a_n-1 + d

• a_n = a_n-1 * r

• a_n = a₁ + d(n-1)

• a_n = a₁ * r^n-1

Which sequence is represented by the equation a_n = 2(7)^n-1 ?

• 7, 14, 28, 56...

• 2, 14, 98, 686...

• 2, 9, 16, 23...

• 7,9,11,13...