Question

Is the following sequence arithmetic? if so, identify the common difference. 18, 13, 8, 3, . . .

Answer 1

Yeah!! It's the A.P. because it has common difference

common difference = 13-18 = -5

so, -5 is the common difference

Answer 2

Yes the sequence 18,13,8,3.... is an arithmetic sequence and the common difference in sequence is -5.

Explanation:

Arithmetic sequence is sequence of a pattern involves adding or subtracting a number to each term to get the next term.

Example: 2,4,6,8,10,12 we have added 2 each term to get the next term.

Consider the given sequence 18,13,8,3....

let
`a_1=18,a_2=13,a_3=8,a_4=3` then

We find the difference of each term,

`a_2-a_1=13-18=-5`

`a_3-a_2=8-13=-5`

`a_4-a_3=3-8=-5`

Yes the given sequence is an arithmetic sequence as difference between each term is same -5.

Thus, the common difference in sequence 18,13,8,3.... is -5.