A monotonically decreasing function is basically the opposite of monotonically increasing functions. If f(x) is a monotonically increasing function over a given interval, then −f(x) is a said to be a monotonically decreasing function over that same interval, and vice-versa.

Is non decreasing function monotonic?

A monotonic function is a function which is either entirely nonincreasing or nondecreasing. A function is monotonic if its first derivative (which need not be continuous) does not change sign.

How do you know if a function is monotonic?

A function that is completely increasing or completely decreasing on the given interval is called monotonic on the given interval. Usually, by looking at the graph of the function one can say whether the function is increasing or decreasing or neither.