# Homework Help: Help me to solve this equation Urgent

1. Apr 30, 2010

### vinodjoshi

Help me to solve this equation.............Urgent

Hi Friends

Can anyone tell me the solution of this equation

where
i is complex no.
A is a constant
D indicates dy/dx or y'(x)

vinodjoshi

2. Apr 30, 2010

### g_edgar

Re: Help me to solve this equation.............Urgent

Looks nonsensical to me. (1) If D indicates dy/dx, then there should be some function following the brace } for the operators to apply to. (2) What do you want to solve FOR?

3. Apr 30, 2010

### Staff: Mentor

Re: Help me to solve this equation.............Urgent

Notwithstanding the urgency of your request, you need to make an attempt at a solution before we can help you.

4. Apr 30, 2010

### Martin Rattigan

Re: Help me to solve this equation.............Urgent

(1) If he had said D indicates d/dx what you say would apply.
(2) Usually you'd want to find y in terms of x and the constants A and "constant". (I assume that "i is complex no." means i=$\sqrt{-1}$.)

5. Apr 30, 2010

### vinodjoshi

Re: Help me to solve this equation.............Urgent

Sorry friends
Let me correct this equation
The correct equation is

6. Apr 30, 2010

### Staff: Mentor

Re: Help me to solve this equation.............Urgent

Multiply both sides by exp(4Ax) and solve the differential equation
(D4 - 8AD3 + 16A2D2 + Ki)y = 0

Here D = d/dx and K = 1/const.

7. Apr 30, 2010

### vinodjoshi

Re: Help me to solve this equation.............Urgent

Well Mark if you examine the equation closely, you will find exp(-4Ax) is not common in whole equation its only common for {D^4-8AD^3+16(A^2)D^2}. Then how to take care of i/(constant)???

8. May 1, 2010

### Staff: Mentor

Re: Help me to solve this equation.............Urgent

OK, I missed that, so what you get is (D4 - 8AD3 + 16A2D2 + Kie4Ax)y = 0

This is pretty messy, but at least it's linear.

9. May 1, 2010

### vinodjoshi

Re: Help me to solve this equation.............Urgent

Thanks for the help but can you explain how to solve it.....................

10. May 1, 2010

### Staff: Mentor

Re: Help me to solve this equation.............Urgent

What is the original problem statement?

11. May 2, 2010

### Redbelly98

Staff Emeritus
Re: Help me to solve this equation.............Urgent

According to Physics Forums policy, you will need to make some attempt at solving the problem yourself first. Surely there is something in your class lecture notes or textbook that is relevant. Make an attempt to share what you know, then others can help you.