How to solve this First Order Differential Equation?

In summary, the conversation discusses the process of solving a differential equation, specifically one with the given form. The individual has tried finding an integrating factor but is unsure of what to do next. They also mention a possible solution given as x^(3)y^(2) + xy^(3) = c and express confusion. Another individual suggests a method for finding an integrating factor and provides a resource for further assistance. Eventually, the first individual realizes their mistake and thanks the other for their help.
  • #1
nontradstuden
54
0
How to solve this differential equation?

dy/dx = - (3yx^(2) + y^(2)) / (2x^(3) + 3xy)


I've tried finding an integrating factor in order to make it exact, but I don't know what to do with this.


The answer is given as x^(3)y^(2) + xy^(3) = c

I'm so confused.


I separated it and found My and Nx. I've also tried finding an integrating factor, but it isn't a function of 'xy'.
 
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  • #2
Presumably you have written it in the form

(3x2y+y2)dx + (2x3+3xy)dy = 0

You are correct that it is not exact. But it may have an integrating factor that is a function of x or y only which will make it exact. Look at

http://www.sosmath.com/diffeq/first/intfactor/intfactor.html

I think you will find one of those two tests works.
 
  • #3
Eh, I just found out what I did wrong. Simple mistake, but took hours to find it because I kept doing it... was dividing by N instead of M...

but Thank you for your assistance!
 

FAQ: How to solve this First Order Differential Equation?

What is a first order differential equation?

A first order differential equation is a mathematical equation that involves a function and its derivative, where the highest derivative present is of first order. It is used to model a wide range of physical phenomena in fields such as physics, engineering, and economics.

How do I solve a first order differential equation?

To solve a first order differential equation, you need to use methods such as separation of variables, integrating factors, or substitution. These methods involve manipulating the equation to isolate the dependent and independent variables, and then integrating both sides to find the solution.

What are initial conditions in a first order differential equation?

Initial conditions refer to the values of the dependent and independent variables at a specific point in the domain of the differential equation. These conditions are necessary to find a unique solution to the equation, as they provide a starting point for the solution.

Can a first order differential equation have more than one solution?

Yes, a first order differential equation can have an infinite number of solutions. This is because the solutions of a differential equation form a family of curves, and there can be multiple curves that satisfy the equation. However, a specific set of initial conditions will determine a unique solution.

What are some real-life applications of first order differential equations?

First order differential equations have many applications in real life, such as predicting population growth, modeling chemical reactions, and analyzing electrical circuits. They are also used in fields like economics, biology, and medicine to understand and predict various phenomena.

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