Discontinuity (Real Analysis)/Examples/Example 1

Example of Discontinuity in the context of Real Analysis
Let $f: \R \to \R$ be the real function defined as:
 * $\forall x \in \R: \map f x = \dfrac 1 {1 - x}$

Then $f$ has a discontinuity at $x = 1$, as $f$ is not defined there.