Journal of the Nigerian Mathematical Society <p>Journal of the Nigerian Mathematical Society (JNMS)</p> <p>JNMS provides a means of communication and exchange of ideas among workers in mathematical sciences (mathematics, mathematical physics, statistics, computer science), and offers an effective method of bringing new results quickly to the public. By doing so the journal establishes an informal vehicle enabling the field of mathematical sciences to be understood in a broad sense. It will include theoretical and experimental results, and fundamental and practical research.<br /><br /></p> Nigerian Mathematical Society en-US Journal of the Nigerian Mathematical Society 0189-8965 On the Stability and Boundedness of Solutions of Aizermann Vector Differential Equations <p>The objective of this paper is to examine certain sufficient conditions for uniform asymptotic stability of trivial solution and uniform ultimate boundedness of all solutions to a certain Aizermann vector differential equation. By constructing an appropriate complete Lyapunov function, we provide sufficient conditions that guarantee the qualitative properties mentioned above. The results of this paper are solutions to the open problems contained in Ezeilo.</p> Adetunji Adedotun Adeyanju Mathew Omeike Olusola Adeniran Biodun Badmus Copyright (c) 2023 2023-12-08 2023-12-08 42 3 169 179 Asymptotic behaviour of solutions of some second order nonlinear differential equations <p>This paper investigates the asymptotic behaviour of solutions of some second order nonlinear ordinary, delay and stochastic differential equations. Order of these differential equations are reduced to system of first order and employed to constructing a suitable complete Lyapunov functions and functional. Standard conditions are imposed on the nonlinear terms to obtain criteria which guarantee the asymptotic behaviour of solutions of the considered equations. Examples are given to illustrate the obtained results. Our results improve and extend some well known results in literature.</p> S. J. Olaleye G. Akinbo O. O. Aduroja A. T. Ademola O. A. Adesina Copyright (c) 2023 2023-12-08 2023-12-08 42 3 181 201 Quasi Central Product of Groups as a Generalization of Certain Product of Groups <p>In this paper we relaxed the condition [H,K] = {e} in the definition of central product and come up with a new product called quasi-central product. We claimed and proved that every central product is quasi-central products but not vice versa. We defined both external and internal quasi-central products and have further shown that, the external and internal quasi-central products are isomorphic.</p> Muntaka Bashir Jibril Namadugu Abdul Iguda Iguda Mansur Muhammad Zubair A. I. Kiri Copyright (c) 2023 2023-12-08 2023-12-08 42 3 203 214 A Seventh–Order Computational Algorithm for the Solution of Stiff Systems of Differential Equations <p>In this paper, we present a computationally cheap second derivative block hybrid method for the<br>numerical solution of systems of stiff initial valued ordinary differential equations. Results of<br>numerical experiments which validates our theoretical results are presented by figures and tables.</p> Richard Akinola Alfred Akoh Copyright (c) 2023 2023-12-08 2023-12-08 42 3 215 242 MORE ENCOMPASSING ALGORITHM FOR APPROXIMATE SOLUTIONS OF SOME NONLINEAR OPERATOR EQUATIONS <p>Whenever a closed form solution for a given problem is not readily available, it is of interest to sort for means of obtaining approximate solution through well defined iterative approach. This work focuses on provision of an iterative method for approximating a common element of set of fixed points of continuous pseudocontractive mappings, set of zeros of inverse strongly monotone mapping, set of solutions of equilibrium problem, and set of common fixed points of countable infinite family of nonexpansive mappings which is a unique solution of a variational inequality problem in the framework of Hilbert space. The iterative method introduced extends, generalizes, improves and unifies some existing results.</p> Grace Nzube Echezona Stanley Okoyeh Nnamdi Nonso Araka Eric Ofoedu Copyright (c) 2023 2023-12-08 2023-12-08 42 3 243 272 A THREE-STEP SIMPSON'S TYPE EXPONENTIALLY-FITTED BACKWARD DIFFERENCE METHOD FOR THE NUMERICAL SOLUTION OF FIRST ORDER ORDINARY DIFFERENTIAL EQUATIONS <p>In this paper, a class of exponential fitting back-<br>ward di erence method (EFBDM) is derived for numerically<br>solving general frst order ordinary di erential equations. This<br>class of method is from the linear multistep method (LMM)<br>derived via the technique of collocation. The power series poly-<br>nomials used as basis function is fitted with an exponential func-<br>tion term. This class of EFBDM is derived for the step num-<br>ber k=3. The method satisfies the basic features of numerical<br>scheme which includes consistency and zero-stability. The con-<br>vergence of the method is also established. This class of 3-step<br>method is compared to already existing methods in literature to<br>establish its eciency in terms of global errors nd they compare<br>favourably with the methods cited.</p> OLUGBADE EZEKIEL FANIYI MARK MODEBEI OLUMIDE OLAIYA Copyright (c) 2023 2023-12-08 2023-12-08 42 3 273 285