The article deals with problem posing in mathematics lessons. It is based on several experimental teaching episodes where problem posing was used. Some examples of posing activities as well as of pupils' problems are given and commented on.
Our aim is to classify and compute zeros of the quadratic two sided matrix polynomials, i.e. quadratic polynomials whose matrix coefficients are located at both sides of the powers of the matrix variable. We suppose that there are no multiple terms of the same degree in the polynomial , i.e., the terms have the form , where all quantities are square matrices of the same size. Both for classification and computation, the essential tool is the description of the polynomial by a matrix equation...