What is meant by a convergent sequence?

1 Answer

A sequence is said to be convergent if it's limit exists.

Else, it's said to be divergent.

It must be emphasized that if the limit of a sequence a_nan is infinite, that is lim_(n to oo) a_n = oo or lim_(n to oo) a_n = -oo, the sequence is also said to be divergent.

A few examples of convergent sequences are:

  • 1/n, with lim_(n to oo) 1/n = 0
  • The constant sequence c, with c in RR and lim_(n to oo) c = c
  • (1+1/n)^n, with lim_(n to oo) (1+1/n)^n = e where e is the base of the natural logarithms (also called Euler's number).

Convergent sequences play a very big role in various fields of Mathematics, from estabilishing the foundations of calculus, to solving problems in Functional Analysis, to motivating the development of Toplogy.