Geometric Sequences Jeopardy!

Arithmetic or Geometric?

100

-5, -10, -15, -20

This is an Arithmetic sequence 

Common difference = -5

200

3, 12, 21, 30...

This is an Arithmetic Sequence?

Common difference = 9

300

-2, -4, -8, -16...

This is a Geometric Sequence?

Common ratio = 2

400

2, -6, 18, -54...

This is a Geometric Sequence?

Common ratio = -3

500

-4, 2, -1, 1/2

This is a Geometric sequence 

Common ratio: -1/2

Find the common difference or ratio

100

The Common Difference of:

-20, -23, -26, -29...

Common difference = -3

200

The Common Ratio of:

3, -6, 12, -24, 48...

Common ratio = -2

300

The Common Difference of:

18, 22, 26, 30...

Common difference = 4

400

The Common Ratio of the Sequence:

3, 9, 27, 81...

Common ratio = 3

500

The Common Ratio of:

1000, 200, 40, 8...

Common ratio = 1/5 or 0.2

Finding General Forms from Terms

100

What is the common ratio if u3=15 and u7=1215

r=3

200

What is the common ratio if u5=30 and u8=-3.75

r=-0.5 or -1/2

300

What is the general form equation of the sequence where u3=10 and u8=31250

un=.4*(5)^n-1

or 2/5*(5)^n-1

400

DAILY DOUBLE

Find the missing terms in the following arithmetic sequence:
u3=8 and u6=-7

un=18+(n-1)-5

OR 

un=-5n+23

500

What is the general form equation of the geometric sequence where u3=24 and u6=192?

un=6*(2)^n-1

Writing Equations (Geometric)

100

Write an equation for the nth term (explicit) of the geometric sequences.

3, 15, 75, 375, 1875, ... 

f(n) = 3*5^n-1

200

Write an equation for the nth term (explicit) of the geometric sequences. 

324, 108, 36, 12, 4, ...

f(n) = 324 * (1/3)^n-1

300

Write an equation for the nth term (explicit) of the geometric sequences. 

1, -2, 4, -8, 16, ....

f(n)=1 * (-2)^n-1

400

Write an equation for the nth term (explicit) of the geometric sequences. Then find the 8th term

3, 6, 12, 24, ...

f(n)= 3*(2)^n-1

f(8)= 384

500

Write explicit equation for the geometric sequence. Then find the 10th term. 

128, 64, 32, 16, 8, ...

f(n)= 128*(1/2)^n-1

The tenth term is 0.25 or 1/4

Finding variables using sequences

100

What is the value of k in the geometric sequence below: k+9, 5k, 7k

k=4

200

What is the value of k in the geometric sequence below

k+2, 5k, 15k

k=3

300

Find the value of k in the geometric sequence below

k, k+3, 4k

k=3, k=-1

400

Find the value of k in the geometric sequence below

k, k+6, 4k

k=6, k=-2

500

Find all values of k in the ARITMETIC sequence below

k²+7, k² , k-5

k=2 and k=-1