Answer:
No, the given sequence is not arithmetic.
Explanation:
Given sequence-
- 5, - 1, 1, 5
Here, a = - 5, a is the first term of the given sequence.
For common difference-
d =

Let

d =

= - 1 -( - 5)
= - 1 + 5
= 4...........................(i)
Let

d =

= 1-( - 1)
= 1 + 1
= 2................................(ii)
Let

d =

= 5 - 1
= 4....................................(iii)
∵ In equation (ii) common difference d is not 4, therefore the given sequence is not arithmetic.