Let $X$ be a vector space. Assume that $f_1,...,f_n$ are linear functionals (may not be bounded) on $X.$
It can be shown that if $$\bigcap_{k=1}^n ker(f_k)=\{0\},$$ then $X$ is finite dimensional.
I would like to know whether the converse holds, that is,
If $X$ is finite dimensional, is it true that $$\bigcap_{k=1}^n ker(f_k) =\{0\}$$ for any $n\in\mathbb{N}?$
It seems true to me as linear functionals on finite dimensional vector space, say $\mathbb{R}^m,$ have trivial kernel. But I do not know how to prove it.
This is obviously false as a theorem reads as follows
The converse also holds apparently and thus numerous counterexamples for your question can be constructed.