Arithmetic and Geometric Sequence

Which sequence is an arithmetic sequence?

• 3, 6, 2, 7, ...

• 3, 6, 12, 24, ...

• 3, 6, 10, 15, ...

• 3, 7, 11, 15, ...

In a certain arithmetic sequence, a₅ = 12 and a₆ = 16. What is a₁ ?

• -8

• -4

• 4

• 8

The explicit formula for a sequence is a_n = 5 − 3n. What is the value of a₂₂ ?

• a₂₂ = -61

• a₂₂ = 61

• a₂₂ = -1

• a₂₂ = -51

Given the arithmetic sequence: 22, 17, 12, 7, . . . . What is the recursive formula that models the sequence?

• f (1) = 7

  f (n) = f (n − 1) − 5

• f (1) = 22

  f (n) = f (n − 1) − 5

• f (1) = 7

  f (n) = f (n − 1) + 5

• f (1) = 22

  f (n) = f (n − 1) + 5

What is the common ratio of this geometric sequence?

500, 200, 80, 32, ...

• -5/2

• -2/5

• 2/5

• 5/2

Which sequence is a geometric sequence with a common ratio of 2?

• 5, 3, 1, -1, ...

• 5, 7, 9, 11, ...

• 5, 10, 20, 40, ...

• 5, 15, 45, 135, ...

Which of the following best describes this sequence?

 $\left\{2,\ -4,\ \ 8,\ -16,\ 32,\ ...\right\}$  

• Arithmetic

• Geometric

• Neither

• Both

Which of the following best describes this sequence?

 $\left\{32,\ 20,\ 8,\ -4,\ ...\right\}$  

• Arithmetic

• Geometric

• Neither

• Both

Which of the following best describes this sequence?

 $\left\{1,\ 3,\ 6,\ 10,\ 15,\ 21,\ ...\right\}$  

• Arithmetic

• Geometric

• Neither

• Both

Which of the following best describes this sequence?

 $\left\{5,\ 8,\ 11,\ 14,\ ...\right\}$  

• An arithmetic sequence with a common ratio of 3.

• A geometric sequence with a common difference of 3.

• An arithmetic sequence with a common difference of 3.

• A geometric sequence with a common ratio of 3.