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

Find the missing term in the geometric sequence: 8, 20, 50, 125, _____.

• 75

• 200

• 250

• 312.5

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

What is the eleventh term of an arithmetic sequence in which a1 = 3 and d = 6?

• 63

• 39

• 69

• 36

What is the difference between an arithmetic sequence and a geometric sequence?

• One is the sum of the numbers and one is just a list of numbers.

• One has a common difference and one has a common ratio.

• One you can write an nth term and one you cannot.

• None of these are correct.

What does a₁ represent?

• Any term

• First term

• Last term

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