Answer
A difference said to be common difference if the difference of any two consecutive terms in arithmetic sequence is constant.
For example consider sequence of 7 terms
= 1 , 5, 9, 13, 17, 21, 25
From above we can see that difference of any two consecutive terms is 4 (always constant) so we can say that it is common difference.
Work Step by Step
For example consider sequence of 7 terms
= 1 , 5, 9, 13, 17, 21, 25
Difference of 25 and 21 = 25 - 21 = 4
Difference of 21 and 17 = 21 - 17 = 4
Difference of 17 and 13 = 17 - 13 = 4
Difference of 13 and 9 = 13 - 9 = 4
Difference of 9 and 5 = 9 - 5 = 4
Difference of 5 and 1 = 5 - 1 = 4
From above we can see that difference of any two consecutive terms is constant so we can say that it is common difference.
