Data expansion:

Divergent sequence refers to non-convergent sequence. Divergent real sequences can be divided into two categories, one is called directional divergent sequences with infinite limit +∞ or -∞, and the other is called non-directional divergent sequences.

Sequence is one of the basic concepts in mathematical analysis. That is, similar mathematical objects are numbered according to natural numbers, and arranged in the order of numbers from small to large. If a sequence is considered as a set, its elements are called the items of the sequence.

Sequence:

Sequence is one of the basic concepts in mathematical analysis. That is, similar mathematical objects are numbered according to natural numbers, and arranged in the order of numbers from small to large. If a sequence is considered as a set, its elements are called the items of the sequence. But the sequence is not a general set, and the items of the sequence have priority, and different items can be the same element.

A sequence can only have finite items, which is called a finite sequence. Sequences with more than finite terms are called infinite sequences, which are usually discussed in mathematical analysis. Sequence can be written as a 1, a2, …, an, …, abbreviated as {an} or {an}n= 1. The nth term An is called the nth term, and when n is regarded as the change of natural number set n, it is also called the universal term.

Sequences usually use different names according to the mathematical objects they contain. For example, a sequence in which all items are numbers is called a sequence, a sequence in which all items are points is called a dot column, and a sequence in which all items are functions is called a function column. Sequences can also be regarded as natural number set n or its part NK = {1, 2, ..., k}, so they are also called integer variables. A sequence is often represented by a series of points on the number axis, so it can be distinguished from a series of points on a straight line.

Disagreement:

In mathematical analysis, the concept opposite to convergence is divergence. The definition of divergence function is: let f(x) be a function defined on r, if there is a real number b >；; 0, for any given c>0, any x 1, x2 satisfies | x 1-x2 | < C, where | f (x1)-f (x2) | > B, function divergence. This definition comes from the inverse of Cauchy's convergence rule.