# Homework Help: Schrodinger equation

1. Apr 24, 2010

### ghostbuster25

ive been asked to show that the function of Y(x) = A sin (x) = 0 is a solution to the equation of

d2Y(x)
dx2

+k2Y(x)=0

where the Y is meant to be the lowercase wavefunctio psi....i just cant get it to work on this :(

basiaclly im completly stuck. Im not really sure what to do!! any help would be much appreciated :)

many thanks

2. Apr 24, 2010

### Cyosis

You're supposed to plug Y(x) into the differential equation and compute the derivatives.

3. Apr 24, 2010

### ghostbuster25

yer thats what ive just been reading but i am unsure of the value of Y

thanks for quick reply :)

4. Apr 24, 2010

### ghostbuster25

sorry what i meant was that i am unsure of the value of A in th function. I understand kind of how to do the rest its just the A that has thrown me

and also i made a mistake the function is Y(x) = A sin (kx) not as stated above

5. Apr 24, 2010

### Cyosis

The A is a constant. It will be pretty obvious what that A is when you plug the solution into the differential equation. Do this and please show your work. I can't say much more until you have done that without giving away the answer.

Last edited: Apr 24, 2010
6. Apr 24, 2010

### ghostbuster25

is a just the quatum numbers (n=1,2,3...)
ha ha i bet its right in front of me isnt it

7. Apr 24, 2010

### Cyosis

Why aren't you plugging the solution into the differential equation as I have asked you to do three times now?

8. Apr 28, 2010

### tomwilliam

Try doing it the other way round: try taking the solution, and differentiating it twice. See what that gives you.