# Continuous function/R/Unbounded on both sides/Surjective/Exercise

Let denote a continuous function having the property that the image of is unbounded in both directions. Show that is

surjective.Let ${}f\colon \mathbb {R} \rightarrow \mathbb {R}$ denote a continuous function having the property that the image of ${}f$ is unbounded in both directions. Show that ${}f$ is

surjective.