Reduction of Order Method - Differential Equation Help

In summary, The problem is asking for help in solving two problems using reduction of order method and without using the y2 formula. The first problem involves an equation with (1-x^2)y'' + 2xy' = 0 and y1 = 1, while the second problem has 4x^2y'' + y = 0 and y1 = [x^(1/2)]ln|x|. The suggested method is to use w=y' for the first problem and to use y=v*y1 for the second problem.
  • #1
bathtub2007
2
0
1. Problem Statement

Okay so I know these appear to be simple but for some reason I am having trouble finding the methods by which to solve them.

Problem 1:

This problem must be solved by reduction of order method and cannot use the y2 formula.

(1 - x^2)y'' + 2xy' = 0; y1 = 1


Problem 2:

This problem must be solved by reduction of order method and cannot use the y2 formula.

4x^2y'' + y = 0; y1 = [x^(1/2)]ln|x|



Homework Equations



y2 / y1 = u (x)

y2 = u (x) * y1 (x)

y' = u'x + u

y'' = u''x +2u'


The Attempt at a Solution



The general form for the problem is:

eq0001M.gif



I have been trying to use Paul's Notes (http://tutorial.math.lamar.edu/Classes/DE/ReductionofOrder.aspx) to help me along the way but I am unable to follow for the lack of the teacher not exactly teaching the problems.


Any help getting towards the right direction would be much appreciated. Thank you.
 
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  • #2
For the first one...try putting w=y' such that w'=y''

Now you have a first order DE.

For the second one, if y=y1 is a solution, then y=v*y1 is another solution.
 

Related to Reduction of Order Method - Differential Equation Help

1. What is the Reduction of Order Method?

The Reduction of Order Method is a technique used to solve second-order linear differential equations by reducing them to a first-order equation. It is particularly useful when one solution of the original equation is known, as it allows us to find a second linearly independent solution.

2. When is the Reduction of Order Method used?

The Reduction of Order Method is used when solving second-order linear differential equations with known solutions. It is often used in cases where the original equation cannot be solved using other techniques such as separation of variables or integrating factors.

3. How does the Reduction of Order Method work?

The Reduction of Order Method works by using the known solution of the original equation to construct a new first-order equation. This new equation can then be solved using standard techniques, such as separation of variables or integrating factors, to find the second solution of the original equation.

4. What are the advantages of using the Reduction of Order Method?

One advantage of using the Reduction of Order Method is that it allows us to find a second solution of a second-order differential equation when one solution is already known. This can be useful in many applications, such as in physics and engineering problems.

Another advantage is that it is a straightforward and systematic method that can be applied to a variety of second-order linear differential equations, making it a valuable tool for scientists and mathematicians.

5. Are there any limitations to the Reduction of Order Method?

One limitation of the Reduction of Order Method is that it can only be applied to second-order linear differential equations with known solutions. It also does not work for non-linear equations or equations with non-constant coefficients.

Additionally, the method may not always produce a solution that is easy to work with or express in closed form. In such cases, numerical methods may be needed to approximate the solution.

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