Existence and multiplicity results for systems of first order differential equations via the method of solution-regions

2019 ◽  
Author(s):  
Marlène Frigon
2018 ◽  
Vol 18 (3) ◽  
pp. 469-485 ◽  
Author(s):  
Marlène Frigon

AbstractIn this paper, we establish existence and multiplicity results for systems of first-order differential equations. To this end, we introduce the method of solution-regions. It generalizes the method of upper and lower solutions and the method of solution-tubes. Our results can also be seen as viability results since we obtain solutions remaining in suitable regions. We give conditions insuring the existence of at least three viable solutions of a system of first-order differential equations. Many examples are presented to show that a large variety of sets can be solution-regions.


First order differential equations can be classified as separable, linear, exact, homogeneous and Bernoulli. Each type has a very systematic method of solution. An analytic method of solution is offered the student for each class of equation whereas integration is essential in the solution process. Hence integration, formulas and steps are important in these kinds of approaches. This study aims to investigate students’ error pattern in solving first order differential equations and focused only to separable, homogeneous and Bernoulli. A test consisting of the three different first-order differential equations was prepared for students. 41 students were asked to solve the equations on the test using appropriate methods. The 41 scripts were examined with a focus on the integration techniques used and the final answers given by students. The results were analyzed using IBM SPSS Statistics 23 and the items such as frequency, mean and standard deviation are used to assess students’ understanding and their ability to solve first order differential equations.


2021 ◽  
pp. 1-19
Author(s):  
Calogero Vetro ◽  
Dariusz Wardowski

We discuss a third-order differential equation, involving a general form of nonlinearity. We obtain results describing how suitable coefficient functions determine the asymptotic and (non-)oscillatory behavior of solutions. We use comparison technique with first-order differential equations together with the Kusano–Naito’s and Philos’ approaches.


2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Jiqiang Jiang ◽  
Lishan Liu ◽  
Yonghong Wu

We consider the existence of positive solutions for a class of nonlinear integral boundary value problems for fractional differential equations. By using some fixed point theorems, the existence and multiplicity results of positive solutions are obtained. The results obtained in this paper improve and generalize some well-known results.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Hailong Zhu ◽  
Shengjun Li

The existence and multiplicity of solutions for second-order differential equations with a parameter are discussed in this paper. We are mainly concerned with the semipositone case. The analysis relies on the nonlinear alternative principle of Leray-Schauder and Krasnosel'skii's fixed point theorem in cones.


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