EUROPEAN JOURNAL OF PURE AND APPLIED MATHEMATICS Vol. 15, No. 3, 2022, 1301-1306 ISSN 1307-5543 – ejpam.com Published by New York Business Global A New Secant Type Method with Quadratic-Order Convergence Zinah F. Salih1,∗, Basim A. Hassan1, Barah M. Sulaiman1 1 Department of Mathematics, College of Computers Sciences and Mathematics, University of Mosul, Iraq Abstract. Using the development of the second approximation, a variation of the standard secant technique for nonlinear problems has been developed. The iterative formula is created using Taylor series expansion, which includes an estimate of the second derivative of Θ(µ). It is demonstrated that the new approaches have quadratic convergence. In comparison with the Newton technique employing seven test functions in the practical application, it turns out that the performance of the method is efficient. 2020 Mathematics Subject Classifications: 65K10 Key Words and Phrases: New Secant Type Method, Iteration Methods, Test functions 1. Introduction Consider the scalar function Θ, which is determined by a single independent variable, µ. Assume we wish to determine the value of µ where Θ(µ) is the minimum value, as shown in [11]. Gradient-based minimization approaches look for spots that satisfy the optimality conditions to find a local minimum. Finding µ∗ that satisfies the first-order optimality requirements, i.e.: Θ ′ (µ∗) = 0 (1) is equivalent to finding the roots of the function to be a minimum of its first derivative. Because of this, root finding methods are effective in function reduction and may be used to identify stationary locations. See [2][7] for further information. In regard to different approximation approaches in terms of convergence, Newton’s method is the most appealing, as illustrated in [10][1]. It works by locally approximating the objective function using a quadratic model that decides on it at a given place. The ∗Corresponding author. DOI: https://doi.org/10.29020/nybg.ejpam.v15i3.4460 Email addresses: zn−f2020@uomosul.edu.iq (Z. F. Salih), basimah@uomosul.edu.iq (B. A. Hassan), barah−mahmood82@uomosul.edu.iq (B. M. Sulaiman) https://www.ejpam.com 1301 © 2022 EJPAM All rights reserved. Z. F. Salih, B. A. Hassan, B. M. Sulaiman / Eur. J. Pure Appl. Math, 15 (3) (2022), 1301-1306 1302 technique can be recurrent indefinitely until the approximation function is optimal. New- ton’s approach, on the other hand, is widely recognized for requiring assessment of the 1st and 2nd derivatives in each iteration, as shown by the iteration formula: See [14][13] for further information. µi+1 = µi − Θ ′ (µi) Θ′′(µi) (2) To avoid this, certain Newton-type methods are referred to as secant methods since they do not require the second derivative. Due to the time-consuming and difficulty involved in determining the second derivative of a function, the formula for iteration, often known as: µi+1 = µi − Θ ′ (µi)(µi − µi−1) Θ′(µi)−Θ′(µi−1) (3) having been developed, more information may be found in [8]. The calculation of Θ and its derivatives consumes the majority of the computational time. Numerous studies have focused on nonlinear issues that do not require the second derivative (see [10][14][4] and [3], despite the fact that a lot of new modified techniques with a higher convergence order have been proposed (e.g. [5][6][15][9]). The derivation of a secant approach based on the second-order Taylor expansion is presented in this study. In comparison to the Newton method, by employing seven test functions, the new method’s performance is evaluated using the most common and exten- sively used criterion: the iterations’ number. 2. A New Secant Type Method An important category of nonlinear optimization problems is the second-order Taylor expansion. We have [12] for the second-order Taylor expansion around the point µi: Θ(µ) ∼= Θ(µi) + Θ ′ (µi)(µ− µi) + 1 2 Θ ′′ (c)(µ− µi) 2 (4) The minimal position at which the derivative of Θ(µ) equals zero may be found by: Θ ′ (µ) ∼= Θ ′ (µi) + Θ ′′ (µi)(µ− µi) = 0 (5) We got the following results from Eqs. (4) and (5): Θ ′′ (µi)(µ− µi) 2 ∼= Θ(µi)−Θ(µ)− 1 2 Θ ′ (µi)(µ− µi) (6) This results in: Θ ′′ (µi) = Θ(µi)−Θ(µ)− 1 2Θ ′ (µi)(µ− µi) (µ− µi)2 (7) The preceding equation may be simplified by substituting µi−1 for µ: Θ ′′ (µi) = Θ(µi)−Θ(µi−1)− 1 2Θ ′ (µi)(µi−1 − µi) (µi−1 − µi)2 (8) Z. F. Salih, B. A. Hassan, B. M. Sulaiman / Eur. J. Pure Appl. Math, 15 (3) (2022), 1301-1306 1303 When we plug Eq. (8) into Eq. (2), we get: µi+1 = µi − Θ ′ (µi)(µi−1 − µi) 2 Θ(µi)−Θ(µi−1)− 1 2Θ ′(µi)(µi−1 − µi) (9) which is the new secant type method. Based on a new secant type technique, the following algorithm is presented: 1. Put ϵ, µ0 (initial point) and the function Θ(µ0), set i = 0. 2. Let i = i+ 1. 3. Set µi = µi−1 − Θ ′ (µi−1) Θ′′ (µi−1) 4. Compute µi+1 = µi − Θ ′ (µi)(µi−1−µi) 2 Θ(µi)−Θ(µi−1)− 1 2 Θ′ (µi)(µi−1−µi) . 5. Stop, if the absolute value of |µi+1 − µi| ≤ ϵ. Convergence rate refers to how quickly an iterative process approaches the numerical solution. 3. Analysis of Convergence A more explicit investigation of the convergence of the new secant iteration has been done since it is critical for the development of optimization algorithms. Theorem 1. Let a sufficiently differentiable function Θ : I → R, where I is an open interval and let µ∗ ∈ I be a zero of Θ. If µ0 converges to µ∗, then the new secant type approach has a quadratic convergence rate. Proof. The new secant’s type method is as: µi+1 = µi − Θ ′ (µi)(µi−1 − µi) 2 Θ(µi)−Θ(µi−1)− 1 2Θ ′(µi)(µi−1 − µi) (10) We may get the following result by removing µ∗ from both sides of Eq. (10): ei+1 = ei − Θ ′ (µi)(ei−1 − ei) 2 Θ(µi)−Θ(µi−1)− 1 2Θ ′(µi)(ei−1 − ei) (11) Where ei = µi+1 − µ∗, as the error after i iterations in the approximate minimum. Now, using Taylor’s theorem in its mean value form: Θ(µ∗) = Θ(µi) + Θ ′ (µi)(µ ∗ − µi) + 1 2! Θ ′′ (µi)(µ ∗ − µi) 2 + 1 3! Θ ′′′ (c)(µ∗ − µi) 3 (12) Z. F. Salih, B. A. Hassan, B. M. Sulaiman / Eur. J. Pure Appl. Math, 15 (3) (2022), 1301-1306 1304 For some c between µ∗ and µi, and because the derivative of the given equation is zero, we get: −Θ ′ (µi) = −eiΘ ′′ (µi) + e2i 2 Θ ′′′ (c) (13) By putting Eq. (13) into Eq. (11), we can get the following conclusion: ei+1 = e2i 1 2 Θ ′′′ (c) Θ′′(µi) (14) This indicates that the convergence order is quadratic. 4. Application Examples In this study, the offered methodologies will be utilized to solve seven test functions. The functions are listed in the tables, along with the minimum points (µ∗), number of iterations (NI), and Execution time (T). A comparison with the Newton Procedure (N- Procedure) is shown to assess the new procedure performance. By using the Matlab program, the calculations have been performed with double pre- cision. If |µi+1 − µi| ≤ ϵ where ϵ = 10−10 achieves in a numerical test, the search is stopped. Lastly, it is evident that the proposed approach is superior to the N-Procedure for all functions where fewer iterations are required to get the desired outcomes. EXAMPLE 1. Function Θ(µ) = cos(µ) + (µ− 2)2, with µ0 = 2. Procedure (NI) µi (T) N- Procedure 4.0 2.3542 0.5790 New Procedure 4.0 2.4333 0.0780 EXAMPLE 2. Function Θ(µ) = eµ − 3µ2, with µ0 = 0.25. Procedure (NI) µi (T) N- Procedure 4.0 0.2045 0.2660 New Procedure 3.0 0.2036 0.0160 EXAMPLE 3. Function Θ(µ) = e−µ + µ2, with µ0 = 1. Procedure (NI) µi (T) N- Procedure 5.0 0.3517 0.3130 New Procedure 4.0 0.2025 0.0780 REFERENCES 1305 EXAMPLE 4. Function Θ(µ) = −µe−µ, with µ0 = 0. Procedure (NI) µi (T) N- Procedure 7.0 1 0.3900 New Procedure 5.0 0.2535 0.0790 EXAMPLE 5. Function Θ(µ) = 0.65− 0.75/(1 + µ2)− 0.65µ tan−1(1/µ), with µ0 = 0.1. Procedure (NI) µi (T) N- Procedure 6.0 0.4809 0.7970 New Procedure 5.0 0.2901 0.0620 EXAMPLE 6. Function Θ(µ) = 0.5µ2 − sin(µ), with µ0 = 2. Procedure (NI) µi (T) N- Procedure 5.0 0.7391 0.4210 New Procedure 3.0 0.7262 0.0630 EXAMPLE 7. Function Θ(µ) = µ4 + 2µ2 − µ− 3, with µ0 = 1. Procedure (NI) µi (T) N- Procedure 7.0 0.2367 0.6870 New Procedure 5.0 0.7624 0.0780 5. Conclusion This research aims to develop a new determined second derivative using a second-order Taylor expansion and a new secant equation. Therefore, it is acceptable to assume that the new secant type technique is more efficient than the Newton method. Some strategies may not always converge to the global minimum, which happens when they fail to converge to the minimum in some circumstances. References [1] Auwal Bala Abubakar, Maulana Malik, Poom Kumam, Hassan Mohammad, Min Sun, Abdulkarim Hassan Ibrahim, and Aliyu Ibrahim Kiri. A liu-storey-type conjugate gradient method for unconstrained minimization problem with application in motion control. Journal of King Saud University-Science, 34(4):101923, 2022. [2] C Edwin and Z Stanislaw. 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