How Do You Solve a Second Order Linear Differential Equation?

So the general solution is U(k,t) = A(k)cos(√ck*t) + B(k)sin(√ck*t).In summary, the conversation is about finding the general solution for the given differential equation and determining the form of the solution. The correct form is U(k,t) = A(k)cos(√ck*t) + B(k)sin(√ck*t) where A(k) and B(k) are arbitrary functions of k.
  • #1
captainjack2000
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0

Homework Statement


I have the equation -(ck^2)U(k,t)=d^2/dt U(k,t). And I need to find the general solution.


Homework Equations





The Attempt at a Solution


I can rearrange this into the form d^2 U/dt^2 + (ck^2)U(k,t)=0 but I am not sure of the form of the solution to this equation.

could someone please give me pointer in the right direction
 
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  • #2
Is it just U(k,t) = Acos(ckt)+Bcos(ckt)?
 
  • #3
Yeah, it's just the differential equation for SHM so that is the solution.
 
  • #4
No it's not. You will get a constant when you do the integration with respect to t, and this constant can depend on k. So the general solution is what you wrote + f(k), where f(k) is an arbitrary function of k.

EDIT: You should have (√c)k instead of ck in the sin and cos.
 
  • #5
Oops! I'm extremely sorry, my previous post is wrong. The constants A and B are the constants of integration, and they should be arbitrary functions of k.
 

FAQ: How Do You Solve a Second Order Linear Differential Equation?

What are differential equations?

Differential equations are mathematical equations that involve an unknown function and its derivatives. They are used to describe the relationship between a function and its rate of change or how it changes over time.

Why are differential equations important?

Differential equations are used to model and study a wide range of phenomena in various fields such as physics, engineering, economics, and biology. They are powerful tools for understanding and predicting the behavior of complex systems.

What are the methods for solving differential equations?

There are several methods for solving differential equations, including separation of variables, integrating factors, power series, and numerical methods such as Euler's method and Runge-Kutta methods.

How do I know which method to use for solving a specific differential equation?

The method used to solve a differential equation depends on its type and order. You can determine the type and order of a differential equation by looking at its highest derivative and the functions involved. It is important to have a good understanding of different methods and their applications to choose the most appropriate one.

Are there any tips for solving differential equations faster?

Some tips for solving differential equations faster include practicing regularly, understanding the problem and its context, breaking the problem into smaller parts, and using appropriate software or technology to assist in calculations. It is also helpful to have a good understanding of the properties of differential equations and their solutions.

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