Let $X$ be a linear space of dimension at least 1, and $x\mapsto \|x\|$ a norm on $X$.

Suppose that a function $f:[0,\infty) \to \mathbb{R}\,$ is given, and define:

$$ N(x):=f(\|x\|), \ x\in X. $$

You are told that $N$ is a norm on $X$.

Choose **ALL** the correct statements from the list: