Ch. 10 Test Review

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

Find the common ratio: 4, -16, 64, -256, ...

• r = -4
• r = 2
• r = -2
• r = 4

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

Given the sequence:

125, 25, 5, ....

Write the explicit rule:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)⁽ⁿ⁾

• a_n = 125 + 5n

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...

To find the next term in an arithmetic sequence…

• add the common difference d

• multiply by the common ratio r

Determine the 3rd term of the sequence.

a₁=5

a_n= 2a_n-1 - 1

• 14

• 13

• 17

• 16

Write a recursive formula for the following sequence:

16,8, 4, 2,...

• a₁=16

  a_n=a_n-1 (2)

• a₁=16

  a_n=a_n-1 (1/2)

• a₁=16

  a_n=a_n-1 + (1/2)

• a₁=16

  a_n=a_{n-1 +} (2)