 The iterative methods used to solve problems of nonlinear programming differ according to whether they evaluate Hessians, gradients, or only function values.While evaluating Hessians (H) and gradients (G) improves the rate of convergence, for functions for which these quantities exist and vary sufficiently smoothly, such evaluations increase the computational complexity (or computational cost) of each iteration.In some cases, the computational complexity may be excessively high.