Bounded Function
Definition1
For a function $f : X \to \mathbb{R}^{n}$, if there exists a constant $M \in \mathbb{R}$ that satisfies the following, $f$ is said to be bounded.
$$ \left| f(x) \right| \le M \quad \text{for all $x \in X, $} $$
설명
다시말해 $f(x)$의 치역이 유계 집합이면 $f$ is called a bounded function.
Walter Rudin, Principles of Mathmatical Analysis (3rd Edition, 1976), p89 ↩︎