- The sequence is constant if .
- The sequence increases if .
- The sequence decreases if .
- The sequence is monotonous if it is either decreasing or increasing.

- An arithmetic sequence whose difference is positive is an increasing sequence.
- An arithmetic sequence whose difference is negative is a decreasing sequence.
- A geometric sequence whose quotient is greater than 1 and whose first term is positive is an increasing sequence.
- A geometric sequence whose quotient is negative is not monotonous.
- The sequence whose general term is equal to is an increasing sequence.
- The number of atoms of Uranium 235 present in an atomic pile, checked every minute, define a decreasing sequence.

Noah Dana-Picard 2007-12-28