Integration using integrating factor

In summary, the conversation discusses how to integrate the equation dy/dx=2y+4x+10 by using an integrating factor and then integrating both sides with respect to x. The next step involves splitting the integral on the right side into two parts and using integration by parts for one of them.
  • #1
xlalcciax
12
0

Homework Statement


Integrate dy/dx=2y+4x+10


The Attempt at a Solution



dy/dx-2y=4x+10
Integrating factor = e^(-2)dx=e^-2x
multiply both sides by IF. (e^-2x)dy/dx-2y(e^-2x)=(e^-2x)(4x+10)
dy/dx(e^-2x y)=(e^-2x)(4x+10)
i don't know what to do next.
 
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  • #2
xlalcciax said:

Homework Statement


Integrate dy/dx=2y+4x+10


The Attempt at a Solution



dy/dx-2y=4x+10
Integrating factor = e^(-2)dx=e^-2x
multiply both sides by IF. (e^-2x)dy/dx-2y(e^-2x)=(e^-2x)(4x+10)
dy/dx(e^-2x y)=(e^-2x)(4x+10)
i don't know what to do next.
The left side is actually d/dx(ye-2x), which is different from dy/dx(ye-2x).

The equation is d/dx(ye-2x) = (4x + 10)e-2x.
Integrate both sides with respect to x, which gives you
[tex]ye^{-2x} = \int (4x + 10)e^{-2x}dx[/tex]

Can you take it from here?
 
  • #3
Mark44 said:
The left side is actually d/dx(ye-2x), which is different from dy/dx(ye-2x).

The equation is d/dx(ye-2x) = (4x + 10)e-2x.
Integrate both sides with respect to x, which gives you
[tex]ye^{-2x} = \int (4x + 10)e^{-2x}dx[/tex]

Can you take it from here?

i know that the left side is ye^-2x but i don't know how to integrate (4x + 10)e^{-2x}
 
  • #4
Split the right-side integral into two integrals. For one of them, use integration by parts. The other one is pretty easy.
 

What is "integration using integrating factor"?

"Integration using integrating factor" is a method used in calculus to solve differential equations. It involves multiplying both sides of the equation by an integrating factor, which helps to simplify the equation and make it easier to integrate.

When is "integration using integrating factor" used?

This method is typically used when solving first-order linear differential equations, where the equation is in the form dy/dx + P(x)y = Q(x). It can also be used for some other types of equations, such as separable or homogeneous equations.

How does "integration using integrating factor" work?

The method works by finding an integrating factor, which is a function that when multiplied by the original equation, makes it easier to integrate. This integrating factor can be found by using an integrating factor formula or by using a method called the "method of inspection". Once the integrating factor is found, the equation can be integrated and solved for the unknown variable.

What are the advantages of using "integration using integrating factor"?

The main advantage of this method is that it can be used to solve a variety of differential equations, including some that cannot be solved by other methods. It also allows for the use of standard integration techniques, making the process more familiar and easier to follow.

Are there any limitations to "integration using integrating factor"?

One limitation of this method is that it can only be used for first-order differential equations. It also requires finding an integrating factor, which can sometimes be challenging and time-consuming. Additionally, this method may not always work for more complex or nonlinear equations.

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