The general formula of increasing sequence is an=a 1+d, where d >；; 0, for a series, if the value of each item is not less than the value of the previous item from the second item of the series, it is called an increasing series.

Calculation method of increasing sequence formula

The summation formula of increasing sequence is (first item+last item) * number of items /2. The sum of series sums the numbers arranged according to a certain law. Finding Sn is essentially a general formula for finding {an}, so we should pay attention to understanding its meaning. The elements in the set are out of order, while the items in the sequence must be arranged in a certain order, that is, they must be orderly.

Common methods include formula method, dislocation subtraction method, anti-addition method, grouping method, split term method, mathematical induction method, general term reduction method and union term summation method. Sequence is an important content of algebra in senior high school, and it is also the basis of learning advanced mathematics. There is an essential difference between the two. The elements in the collection are different from each other, but the items in the series can be the same.