Separable differential equation

In summary, the given differential equation is 4xydx + (x2 +1)dy=0 and it can be solved by using the substitution method and integrating both sides. The final solution is y = C/(x2+1)^2.
  • #1
Dusty912
149
1

Homework Statement


Solve each of the following differential equations:
4xydx + (x2 +1)dy=0

Homework Equations


None

The Attempt at a Solution


4xydx + (x2 +1)dy=0
(x2 +1)dy=-4xydx
dy/y=-(4xdx)/(x2 +1)
∫dy/y=∫-(4xdx)/(x2 +1)
ln|y|=-2ln|x2+1| +C

used u-sub on last step fo u=x2 +1
 
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  • #2
Dusty912 said:

Homework Statement


Solve each of the following differential equations:
4xydx + (x2 +1)dy=0

Homework Equations


None

The Attempt at a Solution


4xydx + (x2 +1)dy=0
(x2 +1)dy=-4xydx
dy/y=-(4xdx)/(x2 +1)
∫dy/y=∫-(4xdx)/(x2 +1)
ln|y|=-2ln|x2+1| +C

used u-sub on last step fo u=x2 +1
Do you have a question?
Your work looks fine to me, but you need to take it one step further and solve for y as a function of x.

After that, check your solution by verifying that it satisifies the original DE.
 

1. What is a separable differential equation?

A separable differential equation is a type of differential equation where the dependent variable and the independent variable can be separated on opposite sides of the equation. This allows the equation to be solved by integrating both sides separately.

2. How do you solve a separable differential equation?

To solve a separable differential equation, you first need to rearrange the equation so that the dependent variable and independent variable are on opposite sides. Then, you can integrate both sides separately and solve for the constant of integration. Finally, you can substitute the constant back into the equation to find the solution.

3. What is the difference between a separable differential equation and a non-separable differential equation?

The main difference between a separable differential equation and a non-separable differential equation is that in a separable equation, the dependent and independent variables can be separated on opposite sides of the equation, whereas in a non-separable equation, they cannot be separated in this way. This makes a separable equation easier to solve because it can be solved by integrating both sides separately.

4. What are some real-world applications of separable differential equations?

Separable differential equations have many real-world applications in various fields of science and engineering. Some examples include population growth models, chemical reactions, and predator-prey relationships in ecology.

5. Are there any tricks or strategies for solving difficult separable differential equations?

There are a few strategies that can be helpful when solving difficult separable differential equations. One strategy is to try to simplify the equation by factoring, using trigonometric identities, or making a substitution. Another strategy is to use separation of variables, where you separate the dependent and independent variables into different equations and then solve for each separately. It is also important to carefully check your work and make sure you have correctly integrated and solved for the constant of integration.

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