Confused on how my professor did this last step, DiffEQ, 2nd OrdER

In summary, the conversation is about a problem for an exam involving a second solution of a given differential equation. The professor is using a method called Abels Theorem and does not want the students to use Euler's method or reduction of order. The student is confused about the last step and has provided a link to their work for clarification.
  • #1
mr_coffee
1,629
1
Hello everyone!
My professor was going over a problem real fast for the exam and now that i went over it again, I'm lost on how he did this last step. He is using a method called Abels Theorum. THe problem says:
Find a second solution of the given differential equation:
t^2y''+3ty' + y = 0;
y1(t) = 1/t;

U could use Eulers, but he doesn't want us to use that method, you could also use reduction of order but that would be more work and he doesn't want us to use that method either. He wants us to use Abels therom which seems to be the simplest out of all of them. Here is my work and I noted where I was confused at the very bottom of the page:


http://suprfile.com/src/1/2bgbtx/lastscan.jpg

Thanks if your confused on my work, let me know and i'll explain!
 
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  • #2
Are you sure that the line shouldn't be [itex]ty_2=ln|t|+C[/itex]
 
  • #3
oooo,
w00t
yeah ur right! the t magically dissapears then reappears!
thanks again assyrian!
 

1. How do I solve a second order differential equation?

There are several methods for solving second order differential equations, including the method of undetermined coefficients, variation of parameters, and Laplace transforms. It is important to understand the specific equation and its initial or boundary conditions in order to choose the appropriate method.

2. What is the purpose of solving a differential equation?

Differential equations describe the relationship between a function and its derivatives, making them useful for modeling various natural phenomena in fields such as physics, engineering, and economics. Solving a differential equation allows us to find the specific function that satisfies the given conditions.

3. Can you give an example of a second order differential equation?

A common example of a second order differential equation is the harmonic oscillator equation, which describes the motion of a mass attached to a spring. It is written in the form mx'' + bx' + kx = 0, where m is the mass, b is the damping coefficient, k is the spring constant, and x is the displacement.

4. What is the difference between first and second order differential equations?

The order of a differential equation refers to the highest derivative present in the equation. A first order differential equation contains only the first derivative, while a second order differential equation contains the second derivative. The order of a differential equation can affect the method used to solve it.

5. How can I check if my solution to a differential equation is correct?

To check if a solution is correct, you can substitute it into the original differential equation and see if it satisfies the equation. Additionally, you can also check if it satisfies any initial or boundary conditions given in the problem. If both of these are true, then your solution is likely correct.

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