Conventions
Throughout this exercise sheet, unless otherwise stated, \(\mathbb{K}\) denotes either \(\mathbb{R}\) or \(\mathbb{C}\), \(E\) denotes a \(\mathbb{K}\)-vector space, and \(n, p\) are positive integers. The reference \(\mathbb{K}\)-vector spaces are \(\mathbb{K}^n\), \(M_{n,p}(\mathbb{K})\), \(\mathbb{K}[X]\), \(\mathbb{K}_n[X]\), \(\mathbb{K}^\Omega\) (functions from a set \(\Omega\) to \(\mathbb{K}\)), and \(\mathbb{K}^\mathbb{N}\) (sequences). The notation \(\mathrm{Vect}(X)\) denotes the subspace spanned by a part \(X\) of \(E\). The dimension theory (existence of a finite basis, dimension formula, theorem of the incomplete basis, rank) is deferred to the next chapter, Finite-dimensional vector spaces; this sheet stays in the dimension-free setting.