Using reduction of order (conceptual) problems

In summary, when solving a nonhomogeneous 2nd order DE with one given solution using variation of parameters, you first need to use reduction of order to get the 2nd solution. The equation should be written in the form of (t-1)^2(y'') - 4(t-1)y' + 6y = 0, and you do not need to divide through with the coefficient of y''. The complementary solution should also be set to g(t)=0 before using reduction of order.
  • #1
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Homework Statement


I have a nonhomogeneous 2nd order DE and I am given one solution to it and told to use variation of parameters?
to get the general solution. First i need to get the 2nd solution though. Should I use reduction of order to get the 2nd solution? If so, then in what form should the equation be in before i start using reduction of order? The complementary solution is the solution to a homogeneous equation right? So should g(t) = 0 before using reduction of order?
heres what I mean..
the equation is:

(t-1)^2(y'') - 4(t-1)y' + 6y = t

so in order to use reduction of order should i write the equation as:
(t-1)^2(y'') - 4(t-1)y' + 6y = 0

and then proceed?

also, do i first need to divide through with the coefficient of y'' or does that matter?

Sorry if I am explaining this sort of retardedlike but I am struggling with it..
pleas help...thanks!

( fyi, the given solution is y_1 = (t-1)^2 )

Homework Equations





The Attempt at a Solution

 
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  • #2
Yes, you should write it as (t-1)^2(y'') - 4(t-1)y' + 6y = 0 before using reduction of order. You don't need to divide through with the coefficient of y''. The complementary solution is the solution to a homogeneous equation, so yes, g(t)=0 before using reduction of order.
 

Related to Using reduction of order (conceptual) problems

1. What is reduction of order in conceptual problems?

Reduction of order is a mathematical technique used to solve second-order differential equations by reducing them to first-order equations. It involves substituting a new variable for the dependent variable in the original equation, which allows for the equation to be solved using basic integration techniques.

2. When should I use reduction of order to solve a problem?

Reduction of order should be used when solving second-order differential equations that cannot be solved using other techniques such as separation of variables or the method of undetermined coefficients. It is particularly useful for problems with non-constant coefficients.

3. What are the steps involved in using reduction of order to solve a problem?

The first step is to substitute a new variable for the dependent variable in the original equation. Then, take the derivative of this new variable and plug it into the original equation, creating a first-order equation. Finally, solve the first-order equation using basic integration techniques to find the original solution.

4. Can reduction of order be used for all types of second-order differential equations?

No, reduction of order can only be used for linear second-order differential equations. It cannot be used for non-linear equations or equations with non-constant coefficients.

5. Are there any limitations to using reduction of order to solve problems?

One limitation is that it can only be used for second-order differential equations. Additionally, it may not always be possible to find a suitable substitution for the dependent variable, making this technique ineffective for some problems. It also requires some level of familiarity with integration and solving differential equations, so it may not be suitable for beginners.

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