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Power Series Methods for Solving Fractal Differential Equations using Least Squares Approximations
Dafar Zuhier Ali #1, Adil AL-Rammahi *2
#1,*2 Faculty of Computer Sciences and Mathematics, University of Kufa, Najaf,Iraq [email protected] , [email protected]
ORCID#1: 0000-0003-3361-0182, ORCID*2: 0000-0003-3856-0663
Issue: Special Issue on Mathematical Computation in Combinatorics and Graph Theory in Mathematical Statistician and Engineering Applications
Article Info
Page Number: 115 - 129 Publication Issue:
Vol 71 No. 3s3 (2022)
Article History
Article Received: 30 April 2022 Revised: 22 May 2022
Accepted: 25 June 2022 Publication: 02 August 2022
Abstract
For introducing of studying the fractal differential Equations, a proposed method for its solution was studied using Power series Methods via least squares approximations. The method depend on the definitions of Riemann-liouville fractional derivatives. The linear non homogenous fractal differential Equations are solved with detailed examples. For checking the errors, many comparisons of solutions with exact solutions and with known solutions.
Keywords:Riemann-liouville, fractal differential Equations, Power series methods, least squares approximations, Fractional residual power series.
2010 AMS: 40Cxx, 40C19
1. Introduction
Fractional calculus theory is a mathematical analysis tool applied to the study of integrals and derivatives of arbitrary order, which unifies and generalizes the notions of integer-order differentiation and n-fold integration [1,2,3,4]. Commonly these fractional integrals and derivatives were not known to many scientists and up until recent years, they have been only used in a purely mathematical context, but during these last few decades these integrals and derivatives have been applied in many science contexts due to their frequent appearance in various applications in the fields of fluid mechanics, viscoelasticity, biology, physics, image processing, entropy theory, and engineering [5,6,7,8] It is well known that the fractional order differential and integral operators are non-local operators. This is one reason why fractional calculus theory provides an excellent instrument for description of memory and hereditary properties of various physical processes. For example, half-order derivatives and integrals proved to be more useful for the formulation of certain electrochemical problems than the classical models [1,2,3,4]. Applying fractional calculus theory to entropy theory has also become a significant tool and a hotspot research domain [9,10] Power series have become a fundamental tool in the study of elementary functions and also other not so elementary ones as can be checked in any book of analysis. They have been widely used in computational science for easily obtaining an approximation of functions [11] In physics, chemistry, and many other sciences this power expansion has allowed scientist to make an approximate study of many systems, neglecting higher order terms around the equilibrium point.
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This is a fundamental tool to linearize a problem, which guarantees easy analysis[12,13 ] The study of fractional derivatives presents great difficulty due to their complex integro-differential definition, which makes a simple manipulation with standard integer operators a complex operation that should be done carefully. The solution of fractional differential equations (FDEs), in most methods, appears as a series solution of fractional power series (FPS) [14,15,16,17] We will study a developed solution method, which is the combination of two methods of the power series and the approximation of least squares with giving some examples and solving them in the developed way and comparing with the real solution as shown in the drawing and the attached tables with examples and programmed in Matlab.
2-Basic concepts of fractal differential equations
Defintion (1):In the theory of fractional calculus, the entire gamma function ฮ(t) plays a substantial turn. An inclusive definition of ฮ(t) is that supplied by Euler limit [17]
ฮ(t) =lim
Nโโ
N!Nt
t(t+1)(t+2)(t+N) , t > 0 (1)
Whilst the beneficial integral convert form is defined by:
ฮ(t)=โซ y0โ tโ1eโu du, R(t) > 0 (2)
Defintion(2):The ฮฑ th order left and right Riemann-liouville integrals of funaction y(x) are defined on the interval (a,b) as following[1][18][22]:
a๐ผ๐ฅ๐ผ y(t) = 1
ะ(ฮฑ) โซax(xโs)y(s)1โฮฑ ds (3) x๐ผ๐๐ผ y(t) = 1
ะ(ฮฑ) โซxb(xโs)y(s)1โฮฑ ds (4)
Where ฮฑ > 0 are called fractional integrals of the order ฮฑ, they are sometimes called left-sides and right-sided fractional integrals respectively.
Defintion (3) : The ฮฑ th order left and right Riemann-liouville drrivative of funaction y(t) are defined on the interval (a,b) are given as[1, 18, 22]
RL ๐ทa,xฮฑ y(t) = 1
ะ(nโฮฑ) dn
dxn โซ (x โ ฯ)ax nโฮฑโ1 y(ฯ)dฯ (5) RL ๐ท๐ฅ,๐๐ผ y(x) = (โ1)n
ะ(nโฮฑ) dn
dxn โซ (ฯ โ x)xb nโฮฑโ1 y(ฯ)dฯ (6) where n โ 1 < ๐ผ < ๐ โ z+.
2.1:the composition of Riemann-liouville fractional integral and derivative
โข If ๐น โ ๐ถ[0, โ),then the Riemann-liouville fractional order integral has the following important property [1],[18]:
Iฮฑ(Iฮฒ f(x)) = Iฮฒ(Iฮฑ f(x)) = Iฮฑ+ฮฒ f(x) where ฮฑ > 0 ๐๐๐ ๐ฝ > 0
= 1
ฮ(ฮฑ + ฮฒ) โซ(x โ t)ฮฑ+ฮฒโ1
x
0
f(t) dt
โข let use consider the fractional derivative of order ฮฑ a fractional derivative of order ฮฒ [2],[19]
๐ท๐ผ(๐ท๐ฝ๐(๐ก)) = ๐ท๐ผ+๐ฝ๐(๐ก)
โข for ๐ผ > 0, ๐ก > 0 [2],[3]
Dฮฑ(Iฮฑf(t)) = f(t)
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โข ๐ท๐ผ(๐๐(๐ก) + ๐๐(๐ก)) = ๐๐ท๐ผ๐(๐ก) + ๐๐ท๐ผ๐(๐ก) [2]
โข ๐ท๐ผ(๐๐(๐ก)) = ๐๐ท๐ผ๐(๐ก) ๐ผ > 0
โข ๐ท๐ผ(๐(๐ก). ๐(๐ก)) = [๐ท๐ผ๐(๐ก)]. ๐(๐ก) + ๐(๐ก)[๐ท๐ผg(t)][2]
โข ๐ท๐ผ(๐(๐ก) + ๐(๐ก)) = ๐ท๐ผ๐(๐ก) + ๐ท๐ผ๐(๐ก) ๐ผ โ ๐
2.2 The derivative of fractal differential equation[2][18]
โข Dฮฑ(xn) = ฮ(nโ1)
ฮ(nโฮฑ+1) xnโฮฑ
โข Dฮฑ(sin ฮฑx) = aฮฑsin (ax +ฯ
2ฮฑ)
โข Dฮฑ(cos ฮฑx) = aฮฑcos (ax +ฯ
2ฮฑ)
โข Dฮฑ (ekx) = kฮฑ ekx
โข Dฮฑ(C) = Cxโฮฑ
ฮ(1โฮฑ)
2.3:leaste square approximation:
Definition(4) Another approach to approximating a function f(x) on an interval a โค x โค b is to seek an approximation p(x) with a small โaverage errorโ over the interval of approximation. A convenient definition of the average error of the approximation is given by[17][18]
๐ธ(๐; ๐) โก [ 1
๐โ๐โซ [๐(๐ฅ) โ ๐(๐ฅ)]๐๐ ] (7)
This is also called the root-mean-square-error (denoted subsequently by RMSE) in the
approximation of f(x) by p(x). Note first that choosing p(x) to minimize E(p; f) is equivalent to minimizing
โซ [๐(๐ฅ) โ ๐(๐ฅ)]๐๐ 2๐๐ฅ (8)
thus dispensing with the square root and multiplying fraction (although the minimums are generally different). The minimizing of (8) is called the least squares approximation problem For a given function
2.4:solution of homogeneous fractal differential eqution
The Power series is a fundamental tool in the study of elementary functions. They have been widely used in computational science for easily obtaining an approximation of functions. In thermal
physics and many other sciences this power expansion has allowed scientist to make an approximate study of many differential equations
Theorem(1): Suppose that u(t) has a FPS representation at t = t0 of the form [19]:
๐ฆ(๐ก) = โโn=0cn(t โ tยฐ)nฮฑ= cยฐ+ c1(t โ tยฐ)๐ผ+ c2(๐ก โ ๐กยฐ )2๐ผ+ โฏ (๐ ๐ก๐๐๐ ) (9)
Where 0 โค ๐ โ 1 < ๐ผ โค ๐, ๐ โ ๐+๐๐๐ ๐ก โฅ ๐กยฐ is called afractional power series about ๐กยฐ,where ๐ก is variable and ๐๐are the coefficients of series and will be of the form[24]
๐๐ =๐ทะ(๐๐ผ+1)๐๐ผ๐ฆ(๐กยฐ) (10)
Theorem(2): Suppose that the fractional power series โโ๐=0๐๐๐ก๐๐ผ has radius of convergence ๐ >
0. If ๐(๐ก) is afunaction defined by ๐(๐ก) = โโ๐=0๐๐๐ก๐๐ผ on
0 โค ๐ก โค ๐ ,Then for ๐ โ 1 < ๐ผ โค ๐ and 0 โค ๐ก โค ๐ we have[21][24]
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Dฮฑf(t) = โโn=0๐๐ะ(nฮฑโฮฑ+1)ะ(nฮฑ+1) t(nโ1)ฮฑ (11) Iฮฑf(t) = โ ๐๐ ะ(nฮฑ+1)
ะ(nฮฑ+ฮฑ+1)
โn=0 t(n+1)ฮฑ(12)
(2.4.1)Fractional residual power series method
we intend to use the FRPS method to solve a class of solid systems In fractional order by replacing FPS expansions within the remaining truncation functions. To do this, we assume that the FPS solution at t = 0 has the following form: The objective of the FRPS algorithm is to obtain an approximate solution supporting the the proposed model. Thus, using the initial conditions, it can be written as follows[25]
๐ฆ = โ ๐๐๐ก๐ผ๐
ะ(๐๐ผ+1)
โ๐=0 (13)
And the solution approximation is ๐ฆ(๐ก) = ๐ยฐ+ โ ๐๐๐ก๐ผ๐
ะ(๐๐ผ+1)
โ๐=1 . (14)
Example(1): consider the fractional differential equation Solve ๐ท๐ผ ๐ฆ โ ๐ฆ = 0
Solution: Suppose that ๐ฆ = โ ๐๐๐ฅ๐ผ๐
ะ(๐๐ผ+1)
โ๐=0 and We substitute it in the given equation[24].
๐๐๐ก ๐ฆ = โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
๐ท12(โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
) โ (โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
) = 0
(โ ๐๐
ะ(๐๐ผ + 1)๐ท12๐ฅ๐๐ผ
โ
๐=0
) โ (โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
) = 0
(โ ๐๐ ะ(๐๐ผ + 1)
ะ(๐๐ผ + 1) ะ(๐๐ผ โ ๐ผ + 1)
โ
๐=0
๐ฅ๐๐ผ) โ (โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
) = 0
(โ ๐๐
ะ(๐ผ(๐ โ 1) + 1)
โ
๐=0
๐ฅ๐๐ผ) โ (โ ๐๐๐ฅ๐ผ๐ ะ(๐๐ผ + 1)
โ
๐=0
) = 0
Let ๐ = ๐ โ 1 ๐ = ๐
(โ ๐๐+1 ะ(๐๐ผ + 1)
โ
๐=0
๐ฅ๐๐ผ) โ (โ ๐๐๐ฅ๐๐ผ ะ(๐๐ผ + 1)
โ
๐=0
) = 0
โ ๐๐+1โ ๐๐
โ
๐=0
( ๐ฅ๐ผ๐
ะ(๐ผ๐ + 1)) = 0๐๐๐ ๐ฅ๐ผ๐
ะ(๐ผ๐ + 1)โ 0 ๐๐+1โ ๐๐ = 0 โ ๐๐(๐ โ 1) = 0 ๐๐ข๐ก ๐๐ โ 0 โ ๐ = ๐ ๐ฆ(๐ฅ) = ๐ยฐ+ ๐1 ๐ฅ๐ผ
ะ(๐ผ+1)+ ๐2 ๐ฅ2๐ผ
ะ(2๐ผ+1)+ ๐3 ๐ฅ3๐ผ
ะ(3๐ผ+1)+โฏ
The genral solution is ๐ฆ = โ ๐๐๐ฅ๐ผ๐
ะ(๐๐ผ+1)
โ๐=0 .
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3. Suggested method for solving nonhomogeneous fractal differential equations power series with the use of least squares approximation
If we had a non-homogenuse linear fractal differential equation in the form for example , Dฮฑy + by = f(x), it is solved by a power series method, which is to substitute for each ๐ฆ =
โ ๐๐๐ฅ๐๐ผ
๐ค(๐๐ผ+1)
โ๐=0 and simplify the expression ๐ท๐ผ๐ฆ + ๐๐ฆ = ๐(๐ฅ)
๐ฆ = โ ๐๐๐ฅ๐๐ผ ๐ค(๐๐ผ + 1)
โ
๐=0
๐ท๐ผโ ๐๐๐ฅ๐๐ผ ๐ค(๐๐ผ + 1)
โ
๐=0
+ ๐ โ ๐๐๐ฅ๐๐ผ ๐ค(๐๐ผ + 1)
โ
๐=0
= ๐(๐ฅ)
โ ๐๐
๐ค(๐๐ผ + 1)๐ท๐ผ๐ฅ๐๐ผ
โ
๐=0
+ ๐ โ ๐๐
๐ค(๐๐ผ + 1) ๐ฅ๐๐ผ
โ
๐=0
= ๐(๐ฅ)
โ ๐๐
๐ค(๐๐ผ + 1)
๐ค(๐๐ผ + 1) ๐ค(๐๐ผ + 1 โ ๐ผ)
โ
๐=0
๐ฅ๐๐ผโ๐ผ + ๐ โ ๐๐
๐ค(๐๐ผ + 1) ๐ฅ๐๐ผ
โ
๐=0
= ๐(๐ฅ)
โ ๐๐
๐ค(๐๐ผ + 1 โ ๐ผ)
โ
๐=0
๐ฅ๐ผ(๐โ1)+ ๐ โ ๐๐
๐ค(๐๐ผ + 1) ๐ฅ๐๐ผ
โ
๐=0
= ๐(๐ฅ)
โ ๐๐
โ
๐=0
[ ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผ + 1 โ ๐ผ)+ ๐ ๐ฅ๐๐ผ
๐ค(๐๐ผ + 1)] = ๐(๐ฅ) We assume the [ ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผ+1โ๐ผ)+ ๐ ๐ฅ๐๐ผ
๐ค(๐๐ผ+1)] = ๐ค๐
โ ๐๐
โ
๐=0
๐ค๐ = ๐(๐ฅ)
๐ยฐ๐คยฐ+ ๐1๐ค1+ ๐2๐ค2+ โฏ + ๐๐๐ค๐ = ๐(๐ฅ) By using least squares approximation
โ= โซ (๐(๐ฆ) โ ๐ฆ)๐๐ 2 (15)
๐(๐ฆ) = โโ๐=0๐๐๐ค๐โ ๐(๐ฅ)(16) ๐ฆ = โ ๐๐
๐ค(๐๐ผ+1)
โ๐=0 ๐ฅ๐๐ผ = โโ๐=0๐๐๐ฃ๐ (17)
We substitute (16), (17) in (15)
โ= โซ [(โ ๐๐๐ค๐
โ
๐=0
โ ๐) โ โ ๐๐
โ
๐=0
๐ฃ๐]
๐
๐
2
โ= โซ [(โ ๐๐(๐ค๐
โ
๐=0
โ ๐ฃ๐) โ ๐)]
๐
๐
2
โ= โซ(๐ยฐ
๐
๐
(๐คยฐโ๐ฃยฐ) + ๐1(๐ค1โ๐ฃ1) + ๐2(๐ค2โ๐ฃ2) + โฏ + ๐๐(๐ค๐โ๐ฃ๐) โ ๐)2
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๐โ
๐๐ยฐ= 2 โซ(๐ยฐ
๐
๐
(๐คยฐโ๐ฃยฐ) + ๐1(๐ค1โ๐ฃ1) + ๐2(๐ค2โ๐ฃ2) + โฏ + ๐๐(๐ค๐โ๐ฃ๐) โ ๐)(๐คยฐโ๐ฃยฐ) = 0
๐โ
๐๐1 = 2 โซ (๐๐๐ ยฐ(๐คยฐโ๐ฃยฐ) + ๐1(๐ค1โ๐ฃ1) + ๐2(๐ค2โ๐ฃ2) + โฏ + ๐๐(๐ค๐โ๐ฃ๐) โ ๐)(๐ค1โ๐ฃ1) = 0
๐โ
๐๐2= 2 โซ(๐ยฐ
๐
๐
(๐คยฐโ๐ฃยฐ) + ๐1(๐ค1โ๐ฃ1) + ๐2(๐ค2โ๐ฃ2) + โฏ + ๐๐(๐ค๐โ๐ฃ๐) โ ๐)(๐ค2โ๐ฃ2) = 0
๐โ
๐๐๐ = 2 โซ(๐ยฐ
๐
๐
(๐คยฐโ๐ฃยฐ) + ๐1(๐ค1โ๐ฃ1) + ๐2(๐ค2โ๐ฃ2) + โฏ + ๐๐(๐ค๐โ๐ฃ๐) โ ๐)(๐ค๐โ๐ฃ๐) = 0
๐ = ๐ค โ ๐ฃ
0 = 2 โซ (๐๐๐ ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐ค๐โ ๐)๐ยฐ 0 = 2 โซ (๐๐๐ ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐ค๐ โ ๐)๐1 0 = 2 โซ (๐ยฐ
๐
๐ ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐ค๐ โ ๐)๐2 0 = 2 โซ (๐๐๐ ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐ค๐ โ ๐)๐๐ 0 = โซ (๐ยฐ
๐
๐ ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐๐โ ๐)๐ยฐ 0 = โซ (๐ยฐ
๐
๐ ๐ยฐ+ ๐1๐1+ ๐2๐2++๐๐๐๐โ ๐)๐1 0 = โซ (๐๐๐ ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐๐โ ๐)๐2 0 = โซ (๐๐๐ ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+โฆ+๐๐๐๐โ ๐)๐๐ 0 = โซ (๐ยฐ
๐
๐ ๐ยฐ๐ยฐ+ ๐1๐1๐ยฐ+ ๐2๐2๐ยฐ+โฆ+๐๐๐๐๐ยฐโ ๐๐ยฐ) 0 = โซ (๐๐๐ ยฐ๐ยฐ๐1+ ๐1๐1๐1+ ๐2๐2๐1+โฆ+๐๐๐๐๐1โ ๐๐1) 0 = โซ (๐๐๐ ยฐ๐ยฐ๐2+ ๐1๐1๐2+ ๐2๐2๐2+โฆ+๐๐๐๐๐2โ ๐๐2) 0 = โซ (๐ยฐ
๐
๐ ๐ยฐ๐๐+ ๐1๐1๐๐+ ๐2๐2๐๐++๐๐๐๐๐๐โ ๐๐๐) Let ๐ = 2 โ ๐ยฐ, ๐1, ๐2
โซ ๐ยฐ๐ยฐ๐ยฐ+ ๐1๐1๐ยฐ+ ๐2๐2๐ยฐ
๐
๐
= โซ ๐๐ยฐ
๐
๐
โซ ๐ยฐ๐ยฐ๐1+ ๐1๐1๐1+ ๐2๐2๐1
๐
๐
= โซ ๐๐1
๐
๐
โซ ๐ยฐ๐ยฐ๐2+ ๐1๐1๐2+ ๐2๐2๐2
๐
๐
= โซ ๐๐2
๐
๐
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โซ ๐ยฐ2
๐
๐
โซ ๐1๐ยฐ
๐
๐
โซ ๐2๐ยฐ
๐
๐
โซ ๐ยฐ๐1
๐
๐
โซ ๐12
๐
๐
โซ ๐2๐1
๐
๐
โซ ๐ยฐ๐2
๐
๐
โซ ๐1๐2
๐
๐
โซ ๐22
๐
๐ ]
[ ๐ยฐ ๐1 ๐2] =
[
โซ ๐๐ยฐ
๐
๐
โซ ๐๐1
๐
๐
โซ ๐๐2
๐
๐ ]
๐๐๐ก
[
โซ ๐ยฐ2
๐
๐
โซ ๐1๐ยฐ
๐
๐
โซ ๐2๐ยฐ
๐
๐
โซ ๐ยฐ๐1
๐
๐
โซ ๐12
๐
๐
โซ ๐2๐1
๐
๐
โซ ๐ยฐ๐2
๐
๐
โซ ๐1๐2
๐
๐
โซ ๐22
๐
๐ ]
= ๐ด,
[
โซ ๐๐ยฐ
๐
๐
โซ ๐๐1
๐
๐
โซ ๐๐2
๐
๐ ]
= ๐ต ๐๐๐ [ ๐ยฐ ๐1 ๐2
] = ๐
And the above described is solved to extract the unknown C values according to the equation (๐ด๐. ๐ด)โ1๐ด๐. ๐ต = ๐ถ (18)
4. implimentations and comparisons of proposed method
We will make a comparison between the solution in the assumed way and the exact solution for the two examples shown below and through Figures (1) and (2) and the data table (1), (2) we will find the error value as shown in the mentioned tables
Example(2) solve the fractal differential๐ท12 ๐ฆ = ๐ฅ2, ๐ผ =1
2 ๐๐๐ ๐ = 4, ๐ฆ(0) = 0 ( ๐ท12 ๐ฆ = ๐ฅ2) โ ๐ท12
๐ท12๐ท12 ๐ฆ = ๐ท12 ๐ฅ2 ๐ท๐ฆ = ๐ค(3)
๐ค(52) ๐ฅ32
๐๐ฆ
๐๐ฅ= 3โ๐2
4
๐ฅ32
๐๐ฆ ๐๐ฅ= 8
3โ๐ ๐ฅ32
โซ ๐๐ฆ = โซ 8
3โ๐ ๐ฅ32 ๐๐ฅ ๐ฆ = 8
3โ๐ ๐ฅ2 5 2
5+ ๐, ๐ = 0 ๐ฆ = 16
15โ๐ ๐ฅ52 is the exact solution and solving the fractal differential eqution by the proposed method equation๐ท12 ๐ฆ = ๐ฅ2
let ๐ฆ = โ ๐๐๐ฅ๐๐ผ
๐ค(๐๐ผ+1)
โ๐=0
2326-9865
Vol. 71 No. 3s3 (2022) 122 http://philstat.org.ph ๐ท12 โ( ๐๐๐ฅ๐๐ผ
๐ค(๐๐ผ + 1) )
โ
๐=0
= ๐ฅ2
โ( ๐๐
๐ค(๐๐ผ + 1) ๐ท12 ๐ฅ๐๐ผ )
โ
๐=0
= ๐ฅ2
โ( ๐๐ ๐ค(๐๐ผ + 1)
๐ค(๐๐ผ + 1)
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2
โ( ๐๐ ๐ค(๐๐ผ + 1)
๐ค(๐๐ผ + 1)
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2
โ( ๐๐
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2
โ ๐๐ ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผโ๐ผ+1)
โ๐=0 = ๐ฅ2let ๐ค๐ = ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผโ๐ผ+1)
โ ๐๐๐ค๐
โ
๐=0
= ๐ฅ2
โ= โซ(๐(๐ฆ) โ ๐ฆ)2
1
0
๐(๐ฆ) = โ ๐๐๐ค๐
โ
๐=0
โ ๐ฅ2๐๐๐ก๐ฃ = ๐ฅ๐๐ผ ๐ค(๐๐ผ + 1)
โ= โซ (โ01 โ๐=0๐๐๐ค๐โ ๐ฅ2โ โโ๐=0๐๐๐ฃ๐)2 ๐ฆ = โโ๐=0๐๐๐ฃ๐
โ= โซ(โ ๐๐๐ค๐
โ
๐=0
โ
1
0
โ ๐๐
โ
๐=0
๐ฃ๐โ ๐ฅ2)2
โ= โซ (โ01 โ๐=0๐๐๐ค๐โ ๐๐๐ฃ๐โ ๐ฅ2)2
โ= โซ(โ ๐๐(๐ค๐
3
๐=0
โ
1
0
๐ฃ๐) โ ๐ฅ2)2 ๐๐๐ก ๐ = 3
โ= โซ(๐ยฐ(๐คยฐโ
1
0
๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)2
๐โ
๐๐ยฐ= 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐คยฐโ ๐ฃยฐ)
1
0
๐โ
๐๐1 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค1โ ๐ฃ1)
1
0
๐โ
๐๐2 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค2โ ๐ฃ2)
1
0
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๐โ
๐๐3 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค3โ ๐ฃ3)
1
0
0 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐คยฐโ ๐ฃยฐ)
1
0
0 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3 โ ๐ฃ3) โ ๐ฅ2)(๐ค1 โ ๐ฃ1)
1
0
0 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2 โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค2 โ ๐ฃ2)
1
0
0 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2 โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค3 โ ๐ฃ3)
1
0
0 =โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐คยฐโ ๐ฃยฐ)
1
0
0 =โซ (๐01 ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค1โ ๐ฃ1) 0 = โซ (๐01 ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค2 โ ๐ฃ2) 0 =โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) + ๐3(๐ค3โ ๐ฃ3) โ ๐ฅ2)(๐ค3โ ๐ฃ3)
1
0
๐๐๐ก ๐ = ๐ค โ ๐ฃ
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+ ๐3๐3โ ๐ฅ2)๐ยฐ
1
0
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+ ๐3๐3โ ๐ฅ2)๐1
1
0
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+ ๐3๐3โ ๐ฅ2)๐2
1
0
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2+ ๐3๐3โ ๐ฅ2)๐3
1
0
โซ ๐ยฐ๐ยฐ๐ยฐ+ โซ ๐1๐1๐ยฐ
1
0
+ โซ ๐2๐2๐ยฐ
1
0
+ โซ ๐3๐3๐ยฐ
1
0
โ โซ ๐ฅ2
1
0
๐ยฐ
1
0
โซ ๐ยฐ๐ยฐ๐1+ โซ ๐1๐1๐1
1
0
+ โซ ๐2๐2๐1
1
0
+ โซ ๐3๐3๐1
1
0
โ โซ ๐ฅ2
1
0
๐1
1
0
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โซ ๐ยฐ๐ยฐ๐2+ โซ ๐1๐1๐2
1
0
+ โซ ๐2๐2๐2
1
0
+ โซ ๐3๐3๐2
1
0
โ โซ ๐ฅ2
1
0
๐2
1
0
โซ ๐ยฐ๐ยฐ๐3+ โซ ๐1๐1๐3+ โซ ๐2๐2๐3
1
0
+ โซ ๐3๐3๐3
1
0 1
0
โ โซ ๐ฅ2
1
0
๐3
1
0
โซ ๐ยฐ๐ยฐ๐ยฐ+ โซ ๐1๐1๐ยฐ
1
0
+ โซ ๐2๐2๐ยฐ
1
0
+ โซ ๐3๐3๐ยฐ
1
0
= โซ ๐ฅ2
1
0
๐ยฐ
1
0
โซ ๐ยฐ๐ยฐ๐1+ โซ ๐1๐1๐1
1
0
+ โซ ๐2๐2๐1
1
0
+ โซ ๐3๐3๐1
1
0
= โซ ๐ฅ2
1
0
๐1
1
0
โซ ๐ยฐ๐ยฐ๐2+ โซ ๐1๐1๐2
1
0
+ โซ ๐2๐2๐2
1
0
+ โซ ๐3๐3๐2
1
0
= โซ ๐ฅ2
1
0
๐2
1
0
โซ ๐ยฐ๐ยฐ๐3+ โซ ๐1๐1๐3+ โซ ๐2๐2๐3
1
0
+ โซ ๐3๐3๐3
1
0 1
0
= โซ ๐ฅ2
1
0
๐3
1
0
[
โซ๐ยฐ๐ยฐ
1
0
โซ ๐1๐ยฐ
1
0
โซ ๐2๐ยฐ
1
0
โซ ๐3๐ยฐ
1
0
โซ ๐ยฐ๐1
1
0
โซ ๐1๐1
1
0
โซ ๐2๐1
1
0
โซ ๐3๐1
1
0
โซ ๐ยฐ๐2
1
0
โซ ๐ยฐ๐3
1
0
โซ ๐1๐2
1
0
โซ ๐1๐3
1
0
โซ ๐2๐2
1
0
โซ ๐2๐3
1
0
โซ ๐3๐2
1
0
โซ ๐3๐3
1
0 ]
[ ๐ถยฐ ๐ถ1 ๐ถ2 ๐ถ3
] =
[
โซ ๐ฅ2
1
0
๐ยฐ
โซ ๐ฅ2
1
0
๐1
โซ ๐ฅ2
1
0
๐2
โซ ๐ฅ2
1
0
๐3 ]
Figure (1): The approximate solution of Example (2) for some ๐ผ = 0.5
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Example(3) solve the fractal differential๐ท12 ๐ฆ = ๐ฅ2โ 2๐ฅ, ๐ผ =1
2 ๐๐๐ ๐ = 3, ๐ฆ(0) = 0 ๐ท12 ๐ฆ = ๐ฅ2โ 2๐ฅ
๐ฆ = 16
15โ๐ ๐ฅ52+ 8
3โ๐๐ฅ32 is the exact solution and solving the fractal differential eqution by the Suggested method equation๐ท12 ๐ฆ = ๐ฅ2โ 2๐ฅ (1)
let ๐ฆ = โ ๐๐๐ฅ๐๐ผ
๐ค(๐๐ผ+1)(2)
โ๐=0
๐ท12 โ( ๐๐๐ฅ๐๐ผ ๐ค(๐๐ผ + 1) )
โ
๐=0
= ๐ฅ2โ 2๐ฅ
โ( ๐๐
๐ค(๐๐ผ + 1) ๐ท12 ๐ฅ๐๐ผ )
โ
๐=0
= ๐ฅ2โ 2๐ฅ
โ( ๐๐ ๐ค(๐๐ผ + 1)
๐ค(๐๐ผ + 1)
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2โ 2๐ฅ
โ( ๐๐ ๐ค(๐๐ผ + 1)
๐ค(๐๐ผ + 1)
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2โ 2๐ฅ
โ( ๐๐
๐ค(๐๐ผ โ ๐ผ + 1) )๐ฅ๐ผ(๐โ1)
โ
๐=0
= ๐ฅ2โ 2๐ฅ
โ ๐๐ ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผโ๐ผ+1)
โ๐=0 = ๐ฅ2โ 2๐ฅlet ๐ค๐ = ๐ฅ๐ผ(๐โ1)
๐ค(๐๐ผโ๐ผ+1)
โ ๐๐๐ค๐
โ
๐=0
= ๐ฅ2
โ= โซ(๐(๐ฆ) โ ๐ฆ)2
1
0
(1)
๐๐๐๐ฅ๐ (๐) ๐๐ฉ๐ฉ๐ซ๐จ๐ฑ๐ข๐ฆ๐๐ญ๐ ๐ฌ๐จ๐ฅ๐ฎ๐ญ๐ข๐จ๐ง๐ฌ ๐๐จ๐ซ ๐ญ๐ก๐ ๐๐ฑ๐๐ฆ๐ฉ๐ฅ๐(๐)
๐ ๐(๐ซ๐๐๐๐๐ ๐๐๐๐๐๐๐๐) ๐(๐ซ๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐ ) ๐ฌ๐๐๐๐
0.0000000 0.0000000 0.0000000 0.0000000
0.1000000 0.0019027 0.0019031 0.0000004
0.2000000 0.0107632 0.0107654 0.0000022
0.3000000 0.0296599 0.0296659 0.0000060
0.4000000 0.0608859 0.0608981 0.0000123
0.5000000 0.1063632 0.1063846 0.0000214
0.6000000 0.1677817 0.1678154 0.0000338
0.7000000 0.2466673 0.2467169 0.0000496
0.8000000 0.3444224 0.3444917 0.0000693
0.9000000 0.4623519 0.4624450 0.0000930
1.0000000 0.6016811 0.6018022 0.0001211
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๐(๐ฆ) = โ ๐๐๐ค๐
โ
๐=0
โ (๐ฅ2 โ 2๐ฅ)๐๐๐ก๐ฃ = ๐ฅ๐๐ผ ๐ค(๐๐ผ + 1)
โ= โซ (โ01 โ๐=0๐๐๐ค๐โ (๐ฅ2 โ 2๐ฅ) โ โโ๐=0๐๐๐ฃ๐)2 ๐ฆ = โโ๐=0๐๐๐ฃ๐
โ= โซ(โ ๐๐๐ค๐
โ
๐=0
โ
1
0
โ ๐๐
โ
๐=0
๐ฃ๐โ (๐ฅ2โ 2๐ฅ))2
โ= โซ (โ01 โ๐=0๐๐๐ค๐โ ๐๐๐ฃ๐โ (๐ฅ2โ 2๐ฅ))2
โ= โซ(โ ๐๐(๐ค๐
3
๐=0
โ
1
0
๐ฃ๐) โ (๐ฅ2โ 2๐ฅ))2 ๐๐๐ก ๐ = 3
โ= โซ(๐ยฐ(๐คยฐโ
1
0
๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2 โ 2๐ฅ))2
๐โ
๐๐ยฐ= 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ))(๐คยฐโ ๐ฃยฐ)
1
0
๐โ
๐๐1 = 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + ๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ)(๐ค1โ ๐ฃ1)
1
0
๐โ
๐๐2= 2โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ)(๐ค2โ ๐ฃ2)
1
0
0 =โซ(๐ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ)(๐คยฐโ ๐ฃยฐ)
1
0
0 =โซ (๐01 ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ)(๐ค1 โ ๐ฃ1) 0 = โซ (๐01 ยฐ(๐คยฐโ ๐ฃยฐ) + ๐1(๐ค1โ ๐ฃ1) + +๐2(๐ค2โ ๐ฃ2) โ (๐ฅ2โ 2๐ฅ))(๐ค2โ ๐ฃ2) ๐๐๐ก ๐ = ๐ค โ ๐ฃ
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2โ (๐ฅ2โ 2๐ฅ))๐ยฐ
1
0
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2โ (๐ฅ2โ 2๐ฅ))๐1
1
0
0 =โซ(๐ยฐ๐ยฐ+ ๐1๐1+ ๐2๐2โ (๐ฅ2โ 2๐ฅ))๐2
1
0
โซ ๐ยฐ๐ยฐ๐ยฐ+ โซ ๐1๐1๐ยฐ
1
0
+ โซ ๐2๐2๐ยฐ
1
0
= โซ(๐ฅ2โ 2๐ฅ)
1
0
๐ยฐ
1
0
โซ ๐ยฐ๐ยฐ๐1+ โซ ๐1๐1๐1
1
0
+ โซ ๐2๐2๐1
1
0
= โซ(๐ฅ2 โ 2๐ฅ)
1
0
๐1
1
0
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โซ ๐ยฐ๐ยฐ๐2+ โซ ๐1๐1๐2
1
0
+ โซ ๐2๐2๐2
1
0
= โซ(๐ฅ2โ 2๐ฅ)
1
0
๐2
1
0
[
โซ ๐ยฐ๐ยฐ
1
0
โซ ๐1๐ยฐ
1
0
โซ ๐1๐2
1
0
โซ ๐ยฐ๐1
1
0
โซ ๐1๐1
1
0
โซ ๐1๐2
1
0
โซ ๐ยฐ๐2
1
0
โซ ๐1๐2
1
0
โซ ๐2๐2
1
0 ]
[ ๐ถยฐ ๐ถ1 ๐ถ2
] =
[
โซ(๐ฅ2 โ 2๐ฅ)
1
0
๐ยฐ
โซ(๐ฅ2โ 2๐ฅ)
1
0
๐1
โซ(๐ฅ2โ 2๐ฅ)
1
0
๐2 ]
Figure (2): The approximate solution of Example (3) for some ๐ผ = 0.5 ๐๐๐๐ฅ๐ (๐) ๐๐ฉ๐ฉ๐ซ๐จ๐ฑ๐ข๐ฆ๐๐ญ๐ ๐ฌ๐จ๐ฅ๐ฎ๐ญ๐ข๐จ๐ง๐ฌ ๐๐จ๐ซ ๐ญ๐ก๐ ๐๐ฑ๐๐ฆ๐ฉ๐ฅ๐(๐)
๐ ๐(๐ซ๐๐๐๐๐ ๐๐๐๐๐๐๐๐) ๐(๐ซ๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐ ) ๐ฌ๐๐๐๐
0.0000000 0.0000000 0.0000000 0.0000000
0.1000000 -0.0456644 -0.0456736 0.0000092
0.2000000 -0.1237768 -0.1238017 0.0000249
0.3000000 -0.2175059 -0.2175496 0.0000438
0.4000000 -0.3196507 -0.3197150 0.0000643
0.5000000 -0.4254528 -0.4255384 0.0000856
0.6000000 -0.5313086 -0.5314156 0.0001069
0.7000000 -0.6342872 -0.6344149 0.0001276
0.8000000 -0.7318976 -0.7320448 0.0001473
0.9000000 -0.8219590 -0.8221244 0.0001654
1.0000000 -0.9025217 -0.9027033 0.0001816