/ / Article

Research Article | Open Access

Volume 2017 |Article ID 7637651 | https://doi.org/10.1155/2017/7637651

Mohammad Alkasassbeh, Zurni Omar, "Generalized Hybrid One-Step Block Method Involving Fifth Derivative for Solving Fourth-Order Ordinary Differential Equation Directly", Journal of Applied Mathematics, vol. 2017, Article ID 7637651, 14 pages, 2017. https://doi.org/10.1155/2017/7637651

# Generalized Hybrid One-Step Block Method Involving Fifth Derivative for Solving Fourth-Order Ordinary Differential Equation Directly

Revised14 Jun 2017
Accepted16 Oct 2017
Published12 Nov 2017

#### Abstract

A general one-step three-hybrid (off-step) points block method is proposed for solving fourth-order initial value problems of ordinary differential equations directly. A power series approximate function is employed for deriving this method. The approximate function is interpolated at while its fourth and fifth derivatives are collocated at all points , , in the interval of approximation. Several fourth-order initial value problems of ordinary differential equations are then solved to compare the performance of the proposed method with the derived methods. The analysis of the method reveals that the method is consistent and zero stable concluding that the method is also convergent. The numerical results demonstrate the superiority of the new method over the existing ones in terms of error.

#### 1. Introduction

In this article, we consider the following general fourth-order initial value problems (IVPs) as shown: with the assumption that . Several phenomena in physical fields such as neural networks, electric circuits, and ship dynamics can be expressed in differential equations (DEs) forms (see [1â€“3]).

Block method is one of the efficient methods proposed in 1953 by [4] to enhance the performance of the numerical methods. In 1967, [5] employed block method to provide the essential starting values needed for the predictor schemes. Subsequently, hybrid methods were initiated by [6], which involve the evaluation of functions off-step (nonstep) points. The introduction of hybrid (off-step) points in block methods has many advantages such as the ability to change step size, utilizing data off-step points, and the most important feature according to [7] is the capability to circumvent zero stability barrier condition ([8]).

To increase the accuracy further and to solve the stiffness problem in ordinary differential equations (ODEs), [9] derived second derivative multistep methods for stiff ODEs. Recently, authors like in [10, 11] proposed high derivative methods for the same reason. The former developed block hybrid-second derivative method for stiff systems, while the latter introduced a Simpsonâ€™s type second derivative method for the solution of a first-order stiff system of IVP. In addition, [12] proposed a continuous fourth derivative method for third-order boundary value problems. Following these scholarsâ€™ footsteps a new generalized three-hybrid one-step fifth derivative method for solving fourth-order ODEs directly using the approach of interpolation and collocation will be proposed.

This article consists of five sections: Section 1 is for the introduction, while Section 2 illustrates the method derivation, where we consider three-off-step points and employing the collocation approach. The analysis of the approach is discussed in Section 3 which includes zero stability, order, consistency, and convergence. Section 4 covers the solution of some mathematical problems to show the performance of the developed method. Finally, a brief conclusion is performed in Section 5.

#### 2. Development of the Method

Let the following power series polynomial be the approximate solution of (1)where and , the number of interpolation and collocation points. Now, differentiating (2) four and five times yieldsInterpolate (2) at , , and collocate (3) at all points , , where produces a system of equations in matrix form as below where . Matrix manipulation is then employed to solve the resulting system (4) for the unknown coefficients , . Substituting the obtained values of the coefficients back into (2) yieldswhere , is the constant step size for the partition of the interval which is given by , , and are undetermined constants listed in Appendix in the Supplementary Material (see Supplementary Material available online at https://doi.org/10.1155/2017/7637651). For simplicity we shall use , , , and .

Calculating the first, second, and third derivatives of (5) produces Evaluating (5) at the noninterpolating points with (6) and (7) at all points , , gives the following general equations in block form:where is an identity matrix of order and The entries of , , , and are listed in Appendix in the Supplementary Material section, while the vectors , , , , , are defined as follows:

#### 3. Analysis of the Method

##### 3.1. Zero Stability

Definition 1. The hybrid block method formula (9) is said to be zero stable if no root of the first characteristic equation has modulus greater than one; that is, , and if then the multiplicity of must not exceed four.

To prove that the roots of the first characteristic equation satisfy the previous definition which imply that As a result, the developed method is zero stable.

##### 3.2. Order of the Method

The linear operator associated with the hybrid block methods formula (9) is defined as Expanding the above equation in Taylor series and combining like terms imply According to [7, 13] method (9) is said to be of order if The term is called the error constant and the local truncation error is given by Comparing like terms of and in (15) produces the coefficients with vector of error constants where