geometric sequences: explicit rule

Is the sequence 2, 4, 12, 48,... geometric?

• yes
• no

Tags

CCSS.HSF.BF.A.2

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

Tags

CCSS.HSF.BF.A.2

Given the sequence:
125, 25, 5, ....
Write the explicit rule:

•  t(n) = (125)(5)⁽ⁿ⁾
•  t(n) = 625(1/5)⁽ⁿ⁾
•  t(n) = 625(5)⁽ⁿ⁾
•  t(n) = 125 + 5n

Tags

CCSS.HSF.BF.A.2

Find the general rule for: 64, -32, 16, -8, …  

• 64(1/2)^n-1
• (-32)^n-1
• 64(-1/2)^n-1
• (32)^n-1

Tags

CCSS.HSF.BF.A.2

Write an explicit rule for the general term of the sequence 5, 15, 45, . . . ?

• a_n = a_n-1 x 3
• a_n = 5(3)^n-1
• a_n = 3(5)^n-1
• a_n = 5 + (n-1)3

Tags

CCSS.HSF.BF.A.2

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

• 7, 14, 28, 56...
• 2, 14, 98, 686...
• 2, 9, 16, 23...
• 7,9,11,13...

Tags

CCSS.HSF.BF.A.2

Write the explicit formula for the following geometric sequence:

10, 20, 40, 80, ...

• a_n = 10(2)^n-1

• a_n = 2(10)^n-1

• a_n = 10(2)ⁿ

• a_n = 2(10)ⁿ

Tags

CCSS.HSF.BF.A.2

Write the explicit formula for the following geometric sequence:

100, 50, 25, 12.5, ...

• a_n = 2(100)^n-1

• a_n = 100(2)^n-1

• a_n = 100(1/2)^n-1

• a_n = (1/2)(100)^n-1

Tags

CCSS.HSF.BF.A.2

Given the rule: a_n = 7(½)^n-1

Identify the first term.

• a_n

• 7

• ½

• n

Tags

CCSS.HSF.BF.A.2

Write the explicit rule for the following geometric sequence:

2, -12, 72, ...

• a_n = 72(-6)^n-1

• a_n = 2(-6)^n-1

• a_n = 2(6)^n-1

• a_n = 72(-6)^n-1

Tags

CCSS.HSF.BF.A.2