Unit 3 Review

Match the recursive formula with the sequence (Arithmetic or geometric)

• a₁=1/5

  a_n=a_n-1+2

• a₁=6

  a_n=a_n-1+3

• 6,9,12....

• a₁=-6

  a_n⁼a_n-1+3

• -6,-3,0

• a₁=1/5

  a_n=a_n-1 *2

• a₁=6

  a_n = 3a_n-1

• 6,18,54

Find the common ratio: 64, -16, 4, -1, ...

• r = -8
• r = -1/4
• r = -4
• r = 4

Determine the first 3 terms of the following sequence.

t₁= -3

t_n=t_n-1(3)

• -3, 9, 27

• -3, -9, -27

• -3, -6, -9

• -3, 6,9

Create the explicit formula for the sequence:

2, 8, 14, ...

• a_n=2+6n

• a_n=-6+6n

• a_n=6n-4

• a_n=4-6n

Write the explicit formula for the sequence given by 3, 6, 12, 24, …

• ^a_n= 3(2)^n-1

• ^a_n= 3+(2)ⁿ

• ^a_n= 3(2)ⁿ

• ^a_n= 3+(2)^n-1

Write a recursive formula for the following sequence:

10, 5, 0, -5,...

• a₁= 10

  a_n= a_n-1 - 5

• a₁= 10

  a_n= a_n-1 + 5

• a₁= 10

  a_n= a_n (5)

• a₁= 10

  a_n= a_n-1 (5)

Given the explicit formula of an arithmetic sequence

• You can find any term using the explicit formula

• Are you kidding? You need the first term and the common difference

Answer explanation

Yes you can. Explicit formula is an equation customized for a particular sequence.

Do you remember that you actually used the first term and common difference to get the explicit formula?

• 6

• 12

• 3

• 1.5

When the expression enclosed in absolute value symbol equals a negative number (eg |4x-7|=-9) the equation has _______________solutions