1. The problem statement, all variables and given/known data Please see the attached file if my inline insertion does not work. 2. Relevant equations ##det(A)=det(A^T)## 3. The attempt at a solution Since a matrix has a determinant of zero only when it's columns are linearly dependent, we look for a set of points [x1 x2] such that the first column of the matrix is linearly dependent. This is about as far as I got and I was wondering if this is the right approach or if there's a much more simpler way to approach this problem.