Minimization of quadratic forms using the Drazin-inverse solution.

We analyse the problem of constrained minimization of the real quadratic functional, subject to the inconsistent system of linear equations, whereis a positive definite or positive semidefinite matrix. Both cases are analysed separately, and respective relationships have been established between the solution of the original problem and the Drazin-inverse solution of the equation. In the special case whenis a positive definite and, we show that the solution of the problem can be represented as a particular-inverse solution. [ABSTRACT FROM AUTHOR]