Are these two general solutions or one general/two particular solutions?

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In summary, the conversation discusses a first order homogeneous differential equation and the confusion over whether a particular solution is part of the general solution.
  • #1
s3a
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Homework Statement


The problem and its answers are attached.

I prefer the first one as (same thing but isolated for y):

y_1(x) = [k_1 * x + x * ln(x)]/[k2 - ln(x)]


Homework Equations


First order homogeneous differential equation.
y = xv, dy/dx = v + x dv/dx


The Attempt at a Solution


I solved this successfully. Given that at some point in the solution of the problem for solving y_1(x), I get a denominator with (x+y), it is my "mathematical duty" to check if x + y = 0 => y = -x is a solution to the differential equation and it is. Because of the nature in which I got this y = -x solution, I am confused as to whether I treat this as one of the two alternatives for a general solution or both together span the one and only general solution.

Any input would be greatly appreciated!
Thanks in advance!
 

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  • #2
Your equation isn't linear, is it? It has a y^2 in it. That would mean a linear combination of solutions isn't necessarily a solution.
 

Related to Are these two general solutions or one general/two particular solutions?

1. Are there any differences between general solutions and particular solutions?

Yes, there are several key differences between general solutions and particular solutions. General solutions are applicable to a broader range of problems and can be used to solve multiple different cases. Particular solutions, on the other hand, are specific to a particular problem and cannot be applied to other cases.

2. How do I know if a solution is a general or particular solution?

A general solution usually includes a variable or constant that can take on different values, making it applicable to multiple problems. A particular solution, on the other hand, will have specific values for all variables and constants. It is important to carefully analyze the problem and the solution to determine if it is a general or particular solution.

3. Can a particular solution also be a general solution?

No, a particular solution cannot also be a general solution. A particular solution is specific to one problem and cannot be applied to other cases, while a general solution is applicable to a broader range of problems. However, a particular solution can be derived from a general solution by assigning specific values to the variables and constants.

4. Are general solutions more useful than particular solutions?

It depends on the problem at hand. General solutions are useful when dealing with a broader range of problems and can save time and effort in finding a solution. However, particular solutions are necessary for solving specific problems and can provide more accurate and precise results.

5. Can a general solution be used to find all possible solutions?

No, a general solution may not be able to find all possible solutions. It can only provide a set of solutions that satisfy the given conditions. There may be other solutions that are not covered by the general solution. It is important to carefully analyze the problem and consider other methods to find all possible solutions.

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