Solve systems with

- Three methods use the jacobian matrix
*f'*(*x*) and their names are terminated with`j_solver`. - The three other methods use approximation for
*f'*(*x*) and use only*f*.

`fsolve`with the option`dnewton_solver``fsolve`with the option`hybrid_solver``fsolve`with the option`hybrids_solver``fsolve`with the option`newtonj_solver``fsolve`with the option`hybridj_solver``fsolve`with the option`hybridsj_solver`

giac documentation written by Renée De Graeve and Bernard Parisse