Application of quasi-Newton algorithm for solving a system of nonlinear equations

This thesis focuses on solving macroeconomic models in the form of a system of nonlinear equations. These systems often exhibit a singular Jacobian matrix, which poses a~challenge in finding their solutions. This work introduces a suitable quasi-Newton method for such situations. Specifically, the Levenberg-Marquardt method and its modified two-step variant are chosen, proving to be effective tools for overcoming issues associated with singular Jacobian matrices. The selection of appropriate numerical methods used within the Levenberg-Marquardt method is also thoroughly examined