Geometric Sequences mini-quiz

Write the explicit formula for the sequence.

-3, 6, -12, 24...

• $a_n=\left(-3\right)\left(-2\right)^{n-1^{ }}$

• $a_n=\left(-3\right)\left(2\right)^{n-1^{ }}$

• $a_n=\left(-2\right)\left(-3\right)^{n-1^{ }}$

• $a_n=\left(2\right)\left(-3\right)^{n-1^{ }}$

Tags

CCSS.HSF.BF.A.2

Write an explicit formula for the sequence.

 $a_3=28,\ r\ =\ 2$  

• 
  

   $a_n=\left(2\right)\left(7\right)^{n-1^{ }}$  
  

•  $a_n=\left(\frac{1}{2}\right)\left(7\right)^{n-1^{ }}$  

•  $a_n=\left(7\right)\left(2\right)^{n-1^{ }}$  

•  $a_n=\left(2\right)\left(-2\right)^{n-1^{ }}$  

Tags

CCSS.HSF.BF.A.2

Find the geometric means of each sequence.

810, ____, ____, _____, 10

• 290, 90, 30

• 300, 100, 33

• 800, 790, 780

• 270, 90, 30

Tags

CCSS.HSF.BF.A.2

What does r represent?

• Radical

• Common difference

• Common ratio

Tags

CCSS.HSF.BF.A.2

What does a₁ represent?

• Any term

• First term

• Last term

Tags

CCSS.HSF.BF.A.2

Find the first four terms of the sequence given the rule:
a_n = 4(5)^n-1

• 20, 100, 500, 2500
• 5, 20, 80, 320
• 4, 20, 100, 500
• 4, 9, 14, 19

Tags

CCSS.HSF.BF.A.2

Given the sequence:

125, 25, 5, ....

Write the rule a_n using the geometric sequence formula:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)^(n-1)

• a_n = 125 + 5n

Tags

CCSS.HSF.BF.A.2