The Vandermonde matrix is the $n\times n$ matrix whose $(i,j)$-th component is $x_j^{i-1}$, where the $x_j$ are indeterminates. It is well known that the determinant of this matrix is $$\prod_{1\leq i < j \leq n} (x_j-x_i).$$ There are many known proofs of this fact, using for example row reduction or the Laplace expansion ([here][1]), a combinatorial proof by Art Benjamin and Gregory Dresden ([here][2]), and another (slightly less) combinatorial proof by Jennifer Quinn ([here][3], unfortunately not open access). An easy proof follows by noting that the variety of the determinant contains (as a set) the variety of $x_i-x_j$ for all $i < j$ and then by computing the degree of the determinant as a polynomial in the $x_i, x_j$, though I don't know a reference for this proof. Given that this result is amenable to such a wide variety of proofs (the above list contains three somewhat different flavors of proof---linear algebraic, combinatorial, and algebra-geometric), I have the following question: >Does anyone know a *geometric* proof of this result? For example, one might compute the volume of the parallelepiped whose vertices are given by the rows or columns of this matrix in a clever way. Ideally this would not just boil down to row reduction. [1]: http://www.proofwiki.org/wiki/Vandermonde_Determinant [2]: http://home.wlu.edu/~dresdeng/papers/VDM.pdf [3]: http://www.sciencedirect.com/science/article/pii/S0378375810000406