Most of what a devops person does is in fact development but it is of the non value adding variety. Basically a devops person spends the vast majority of their time configuring common off the shelf software, scripting this or that, etc.
A singular matrix is a matrix which has no inverse because its determinant is zero. If you recall, the inverse of a matrix is. 1/ ad-bc multiplied by: [ d -b ] [-c a ] If ad-bc = 0, then the inverse matrix would not exist because 1/0 is undefined, and hence it would be a singular matrix. E.g.
Let B be any matrix that is row equivalent to a matrix A. Then row(B) =row(A). See the theorem on p. 13. Theorem 3.21. Let A be an mÂ£n matrix and let N be the set of solutions. of the homogeneous linear system A~x =~0. Then N is a subspace of Rn. Deï¬nition. Let A be an mÂ£n matrix. The null space of A is the subspace. of Rn consisting of solutions of the homogeneous linear system A~x =~0.