1. Introduction
In most scientific and engineering applications, the problem of finding the solution of nonlinear equations have become an active area of research. Many researchers have explored various order iterative methods to find solutions of the nonlinear equations using various techniques such as homotopy perturbation technique, variational iterative methods and decomposition technique, for details, see [
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11]. Firstly, Traub [
12] initiated the study of the iterative methods for the solution of the nonlinear equations and introduced a basic quadratic convergent Newton iterative method for the solution of the nonlinear equations, which have much significance in the literature. Later on, in order to improve efficiency and local order of convergence of the Newtons method, Cordero and Torregrosa [
13], Frontini and Sormani [
14], Hasanov [
15], Weerakoon and Fernando [
16] and Ozban [
17] have presented different modifications of the Newton’s method using quadrature rules. Daftardar-Gejji and Jafari [
18] have used different modifications of Adomian decomposition method [
19] and suggested a simple technique that does not need derivative evaluation of the Adomian polynomial, which is major advantage of using this technique over Adomian decomposition method. Saqib and Iqbal [
20] and Ali et al. [
21,
22] have used this decomposition technique and developed a family of iterative methods with better efficiency and convergence order for solving the nonlinear equations. This study shifts the paradigm of determining higher order iterative methods for solving the nonlinear equations towards the
q-analogue of the iterative methods in the
q-calculus.
In the last quarter of the 20th century,
q-calculus appeared as an amalgamation of mathematics and physics (see [
23,
24,
25,
26,
27,
28,
29]), and much consideration has been given by many researchers because of its wide range of applications in many fields of mathematics such as combinatorics, theory of relativity, mechanics, number theory and orthogonal polynomials. Firstly, Jackson [
30] introduced the
q-Taylor’s formula. Then, Jing and Fan [
31] derived
q-Taylor’s formula with its
q-remainder by using the
q-differentiation approach and established results on the
q-remainder in the
q-Taylor’s formula. Ernest [
32] presented the four different
q-Taylor’s formulas along with
q integral remainder. Prashant et al. [
33] have used the
q-Taylor’s formula and investigated the
q-analogue of the iterative methods, particularly the
q-analogue of generalized Newton Raphson method and the
q-analogue of the Newton Raphson method for the solution of algebraic transcendental equations and compared the accuracy of the results obtained by the classical methods. Many linear and nonlinear models appearing in science and engineering problems can be modeled by using the
q differential equations. Jafari et al. [
34] have adopted Daftardar decomposition technique for solving the
q difference equations and also determined the convergence of the method.
In this study, we determine the
q-analogue of the iterative methods proposed and suggested by Noor and Noor [
35] and Ullah et al. [
36] with the help of the
q-Taylor’s series and decomposition technique [
14].
Now, we recall some of the basic results in the area of the
q-calculus [
37] for
that will support the development of our proposed
q-iterative methods for the solution of the nonlinear equations.
Let
q∈(0,1) the
q-integer be defined as:
For
q factorial and for
, the
q binomials are defined as:
Definition 1 (see [
37])
. The q-derivative for real valued continuous function is defined as followsWhen , then the q-derivative is reduced to the standard derivative. Furthermore, the q-derivative can be represented as , and it is known as the Jackson Derivative. The higher order q-derivative for the function is given as Definition 2 (see [
37])
. The q-derivative of product and quotient of function and is defined as follows Definition 3 (see [
30,
31,
32])
. Let be a continuous function on some interval and [a,b] then Jackson q-Taylor’s formula is given as:where,where and are all q-derivatives. The rest of this article is organized as follows: in
Section 2, the structures of the
q-iterative methods will be designed by proposing the Lists A–C. In
Section 3, we deal with the convergence analysis of the proposed
q-iterative methods, and it is established that these methods have the same order of convergence as the classical methods for
. In
Section 4, we present some of the examples to check the efficacy and performance of these methods. Furthermore, the comparisons of the results obtained by
q-iterative methods with the previously known iterative methods will be discussed in the same section.
Section 5 explores a general form of the
q-iterative method based on the proposed iterative methods. Finally, the findings of our article are given in
Section 6.
2. Construction of the -Iterative Methods
In this section, some new different order multi-step
q-iterative methods are constructed by considering the Taylor’s series in the
q-calculus. Here, we consider the nonlinear equation
Suppose that
is the root of Equation (
8) and
is an initial guess in the neighborhood of
. By the same technique used in [
28], we rewrite the nonlinear Equation (
8) as the coupled system of equations by using the Taylor’s series in the neighborhood of
in the
q-calculus:
Since
, the relation (
10) can be written as:
where
and
is a nonlinear operator and
c is treated as constant.
It is noted that if we consider
as an initial guess, then from (
10), we have
It is wort mentioning that Equation (
15) plays a very significant role in the development of new multi-step
q-iterative methods. Now, we establish a sequence of higher order iterative methods implementing the decomposition technique presented by Daftardar-Gejji and Jafari [
18]. The main idea behind the implementation of this technique is to find out the solution of
q-type functional Equation (12) in terms of infinite series:
Now, we decompose the operator
defined in (
14), such as:
From the Equations (
12), (
16) and (
17), we have
which generates the following iterative scheme
Theorem 1 (see [
34])
. If M is a contraction mapping, the defined series in (
16)
is absolutely convergent. Proof. If
M is a contraction mapping, we see that
then in view of (
19), we have
So, the series
x=
converges uniformly and absolutely to the solution of Equation (
12) (see [
38]). It is noted that
x is approximated by
and thus
.
This completes the proof. □
Our iterative techniques proceed with the following algorithms:
- List A:
From (
19), we have for
This formulation suggests the following iterative scheme for solving the nonlinear Equation (
8). Now, for the given initial guess
, the approximate solution is computed by the iterative representation
This represents the Newton’s method in the
q-calculus which has quadratic convergence. It is proved by Singh et al. [
33].
By replacing the value of the
q-derivative in (
23), we have
This method resembles the method of secants (chords).
Now, with the help of (
10) and (
19), we get
- List B:
From (
19), we have for
By using (
22) and (
26), we have
This formulation suggests the following iterative scheme for solving the nonlinear Equation (
8).
For the given initial guess
, the approximate solution is computed by the following iterative method:
This is
q-analogue of Chun method [
3], which has cubic convergence for
. The error term for this algorithm is computed in Theorem (2).
By using (
10), (
19) and (
26), we can obtain
- List C:
Again, from (
19), we have for
By using (
22) and (
31), we get
This formulation allows us to suggest the following iterative method for solving the nonlinear Equation (
8).
For the given initial guess
, the approximate solution is computed by the following iterative method:
This is
q-analogue of convergent iterative method was investigated by Ullah et al. [
36]. Furthermore, it has fourth order convergence for
q = 1. The Error equation for this algorithm is computed in Theorem (2).
4. Numerical Examples and Comparison Results
This section elaborates on the efficacy of algorithms introduced in this paper with the support of examples. All the numerical experiments are performed with Intel (R) Core [TM] 2 × 2.1 GHz, 12 GB of RAM, and all the codes are written in Maple. We use and obtain an approximated simple root rather than the exact based on the exactness of the computer.
For the computational work, we use the following stopping criteria:
Abbreviation is used for classical iterative method and for the q-analogue of classical iterative method, and term div is used for divergence of method.
Recall the classical List 2.2 in [
35] (
), defined by
and the classical List 2.3 in [
36] (
), defined by
For simplicity, we denote the iterative Lists B and C by
and
, respectively. The computational results are presented in
Table 1,
Table 2,
Table 3,
Table 4,
Table 5 and
Table 6 to elaborate the performance and efficacy of our
q iterative methods that is the main motivation of transformation of the classical methods towards the
q-iterative methods.
For simplicity, initially in Examples 1–3, we check the performance of q-iterative methods with the classical methods for different values of q up to three iterations. Similarly, we can check the performance of the q-iterative methods for the different values of q for the rest of the iterations until we achieve the desired accuracy.
Example 1 (see [
3])
. We consider the nonlinear equation: The exact solution for this example is
. We take
as an initial guess.
Table 1 shows the computation of
and
for
and different values of
q by using
.
Proceeding in the way of
Table 1, we get
for different values of
q, which is the required solution. One can observe from
Table 1 that more accurate values of
s can be obtained when
q approaches towards one and for which
tend towards zero. The values of
= 2.746138e + 01,
= 5.942719e + 00,
= 5.488326e − 01 calculated by
at
q = 0.9999 are closer to zero as compared to the values
= 2.747477e + 01,
= 5.949309e + 00,
= 5.505169e − 01 calculated by
. Furthermore, Equation (
51) converges towards the root
= 1.2076478271 for
q = 0.9999 and
= 4.435401e − 12.
Table 2 shows the computation of
and
for
i = 1, 2, 3 for different values of
q by using the List C
.
Proceeding in the way of
Table 2, we get the required solution
x = 1.2076478271. From
Table 2, we see that if
q approaches one, we can obtain more accurate values of
s for which
s tends towards zero, where
. It is also observe that the values of
= 2.117115e + 01,
= 2.896627e + 00,
= 3.622758e − 02 at
q = 0.9999 calculated by
are closer to zero as compared to the values of
= 2.118172e + 01,
= 2.900487e + 00,
= 3.644647e − 02 calculated by
. Furthermore, Equation (
51) converges to the root
= 1.2076478271 for
q = 0.9999 and
= 1.424874e − 20.
Example 2 (see [
39] (Population growth model))
. Consider the nonlinear equationThis equation appears in the mathematical modeling of the growth of population over short periods of time, where λ denotes the constant birth rate of population whose value needs to determined.
For computational work, we take = 1.5 as an initial estimate. The solution of this example approximated to 16 decimal digits is 0.1009979296857498. In Table 3, we compute the values of and for different values of q by using . Proceeding as the way of Table 3, we get the required solution . From Table 3, It can easily observe that we obtain more accurate values of when q approaches one and for which tend towards zero. The values of = 6.591112e + 05, = 2.736999e + 04, = 4.839200e + 00 at q = 0.9999 computed by are closer to zero as compared to the other values of = 6.592007e + 05, = 2.738286e + 04, = 4.850247e + 00 computed by . Furthermore, Equation (
52)
converges towards the root = 0.1009979297 in the fifth iteration for q = 0.9999 and = 4.545278e − 22. Meantime, in Table 4, we compute the values of and for different values of q by using . We can observe from Table 4 that we get more accurate values of when q approaches one and for which tend towards zero. In addition, the values of = 4.206350e + 05, = 2.169407e + 03, = 3.799508e − 06 calculated by at are closer to zero as compared to the values = 4.207000e + 05, = 2.171013e + 03, = 3.859455e − 06 calculated by . Furthermore, Equation (
52)
converges towards the root in the fourth iteration for q = 0.9999 and = 4.103556e − 22. Example 3 (see [
40])
. Consider the van der Waal’s equationThis equation is used to interpret the real and ideal gas behavior that has been converted to the non-linear form after choosing the appropriate values of the parameters. Its exact solution is x = 1.92984624284786221849. Here, we take = 3.10.
By proceeding as the above table, we can obtain the required solution x = 1.9298462428. From Table 5, we can observe that we get more accurate values of for which tend towards zero when q approaches one. The values of = 4.378340e − 01, = 7.835843e − 02, = 1.283785e − 02 at q = 0.9999 computed by are closer to zero as compared to the values of = 4.379863e − 01, = 7.842636e − 0, = 1.286153e − 02 computed by . Furthermore, Equation (
53)
converges towards the root = 1.92984624284786221850 in the seventh iteration for q = 0.9999 and = 3.081547e − 18. The computational results obtained from Table 6 illustrate the accuracy of the values of when q approaches one and for which tend towards zero. Moreover, the values of = 3.105124e − 01, = 3.856881e − 02, = 3.623214e − 03 at q = 0.9999 computed by , are closer to zero as compared to = 3.106207e − 01, = 3.860481e − 02, = 3.632441e − 03 computed by . Furthermore, Equation (
53)
converges towards the root = 1.92984624284786221849 in the sixth iteration for q = 0.9999 and = 2.935505e − 21. 4.1. Error Analysis and Application of the q-Iterative Methods
Error is considered as the difference between a true value and an estimate (see [
39]), or an approximation, it can easily be observed from the numerical values that if we compute the errors of
q-iterative methods than they fluctuate for different values of
q. The error decreases when
q approaches to the extreme values between 0 and 1. In view of this result, the
q-iterative methods are calculated for a large value of
, which will approximate the ordinary iterative methods.
List B |
Nonlinear equation | True Solution | Approximate solution at q = 0.9999 | Error |
Equation (51) | 1.20764782713091892701 | 1.20764782713091892700 | 7.187741e-21 |
Equation (52) | 0.10099792968574978895 | 0.10099792968574978895 | 3.394397e-28 |
Equation (53) | 1.92984624284786221849 | 1.92984624284786218283 | 3.565288e-17 |
List C |
Nonlinear equation | True Solution | Approximate solution at q = 0.9999 | Error |
Equation (51) | 1.20764782713091892701 | 1.20764782713091892701 | 7.016521e-22 |
Equation (52) | 0.10099792968574978895 | 0.10099792968574978895 | 3.064831e-28 |
Equation (53) | 1.92984624284786221849 | 1.92984624284786221845 | 3.396321e-20 |
4.2. Comparison of the Classical and q-Analogue of Iterative Methods
Here, we check the robustness and efficiency of our new iterative methods by considering some of the nonlinear equations. Furthermore, we compare the standard Newton’s method (
), fourth order Chun method (
) (see [
3]),
and
with our new iterative methods
and
. In
Table 7, we display the number of iterations (
), the approximate root
, the value
and
be the distance between two successive estimations. It is important to mention that in order to get better computational results of the
q-iterative methods, we take the value of
.
Table 7 compares the solutions obtained by using the classical and our the
q-iterative methods. The results show that our
q-analogue iterative methods
and
give the same results as the classical methods
and
. The functions
are not differentiable at
and
, respectively, when we choose
and
as initial guesses for
and
, respectively. Then, the iterative methods:
and
fail, while the new iterative methods
and
are applicable and give rapid convergent results.
Remark 1 (see [
12])
. The efficiency index is considered as , where P represents the order of the method and m is the total number of function evaluations per iteration necessary by the method.Efficiency index of is .
Efficiency index of is .
Efficiency index of is .
Efficiency index of is .
We conclude that the efficiency indexes calculated by and are the same as those calculated by and .