Question

How to find selection of terms in arithematic sequence. i think no one know the answer

Answer 1



1

Find the common difference for the sequence. When you are presented with a list of numbers, you may be told that the list is an arithmetic sequence, or you may need to figure that out for yourself. The first step is the same in either case. Select the first two consecutive terms in the list. Subtract the first term from the second term. The result is the common difference of your sequence.[1]

For example, suppose you have the list 1,4,7,10,13.... Subtract 4-1 to find the common difference of 3.

Suppose you have a list of terms that decreases, such as 25,21,17,13…. You still subtract the first term from the second to find the difference. In this case, that gives you 21-25=-4. The negative result means that your list is decreasing as you read from left to right. You should always check that the sign of the difference matches the direction that the numbers seem to be going.