Question

Tell whether or not each sequence is an arithmetic sequence.

15,13,11,9,...

4,7,10,14,...

Answer 1

They’re both arithmetic because the pattern for the first one is add 2, and second is add 3. As long as you can see a pattern of addition or subtraction for the whole thing then it is arithmetic.

Answer 2

Explanation:

• 15, 13, 11, 9, .....
• Here, the common difference is 2 and same in all the cases:
• 13 - 15 = -2
• 11 - 13 = -2
• 9 - 11 = -2

So, this is an AP.

• 4, 7, 10, 14, ......
• Here, the common difference is not same in all the cases:
• 7- 4 = 3
• 10 - 7 = 3
• 14 - 10 = 4

So, this is not an AP.

Hope it helps :)