Geometric Sequences

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

• yes

• no

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

Tags

CCSS.HSF.BF.A.2

Write the explicit formula for the geometric sequence 7, -7, 7, -7

• a_n = 7(1)ⁿ

• a_n = 7(-1)ⁿ

• a_n = 7(-1)^n-1

• a_n = -1(7)^n-1

What is the 14th term of the geometric sequence 3, 9 ,27, 81

• 14,348,907

• 4,782,969

• 1,594,323

• 45

What does r represent?

• Radical

• Common difference

• Common ratio

What does a₁ represent?

• Any term

• First term

• Last term

Select all Geometric Sequences

• 3,6,9.12.15,18

• 78,39/4,39/32,39/64,39/512

• 6,4,8/3,16/9,32/27

• 5,5/3,5/9,10/27,40/81

Find the 10th term if a₁=13 and the common ratio is 2

• 9

• 6656

• 13312

• 26

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)