Common Difference
What is the common difference
6,12,18,24,.....
CD: 6
What is the common ratio?
3, 15, 75...
CR: 15/3= 5
Arithmetic, Geometric, or neither. Explain why?
2, 5, 8 ....
Arithmetic:
CD: 5-2=3
Write explicit formula for:
3,9,27....
An=3(3)^n-1
Find the 4th term:
10, 20, 30 ....
Answer 40
What is the common difference?
30, 20, 10 ....
CD: 20-30 = -10
What is the common ratio?
2, -8, 32 .....
CR: -8/2= -4
Arithmetic, Geometric, or neither. Explain why?
5, -30, 180, ....
Geometric
CR: -6
Write the explicit formula:
4,-16, 64 ...
An= 4(-4)^n-1
Find the 8th term:
2, -10, 50
-156250
What is the common difference?
6,-6,-18....
-6-6=-12
CD: -12
What is the common ratio?
25, -125, 625....
CR: -125/25= -5
Arithmetic, Geometric, or neither. Explain why?
5, 10, 15, 25
Neither
Write the explicit formula?
2, -20, 200 ....
An= 2(-10)^n-1
Find the 12th term
3, 12, 48 ....
12,582,912
What is the common difference?
-14, -8, -2...
CD: -8 - (-14)
-8+14=6
What is the common ratio?
20, 5, 1.25
CR: 5/20 = 1/4
Arithmetic, Geometric, or neither. Explain why?
3,-9, 27, -81
Geometric:
CR = -3
Write the explicit formula?
40, 20, 10, 5 ....
An=40(1/2)^n-1
Find the 10th term
1, -1, 1, -1 ....
Answer: -1
What is the common difference?
0.14, 0.28, 0.42...
CD: 0.28-0.14= 0.14
What is the common ratio?
100, -10, 1 ....
CR: -10/100= -1/10
Arithmetic, Geometric, or neither. Explain why?
-0.34, -0.54, -0.74...
Arithmetic:
-0.20
Write the explicit formula?
400, 100, 25 ....
An=400(1/4)^n-1
Find the 15th term:
-7, 21, -63...
-33,480,783