Asymptotically Equal Real Functions/Examples/sin x and x

Example of Asymptotically Equal Real Functions
Let $f: \R \to \R$ be the real function defined as:
 * $\forall x \in \R: \map f x = \sin x$

Let $g: \R \to \R$ be the real function defined as:
 * $\forall x \in \R: \map g x = x$

Then:
 * $f \sim g$

as $x \to 0$.