# How is integral finished? and what integral equation used?

1. Jan 1, 2016

2. Jan 1, 2016

### BvU

Hello zq,
Is there a context to this question ? What is this about ? Any idea what each of the various symbols stands for ?

3. Jan 1, 2016

### zqz51911

sorry for the so simple description
this is a expand F(x) with particle in a box energy eigenfuctions
F(x)=x(x-l) for 0<x<l and F(x)=0 elsewhere
psi is the wave function of ground state particle in a box equation

4. Jan 1, 2016

### BvU

So at the core you need $$\int_0^l x\, sin(ax)\; dx {\rm \quad and \quad} \int_0^l x^2 \,sin(ax)\; dx$$ (with $a = n\pi/l$) , right ?
Ever met these integrals ?

5. Jan 1, 2016

thanks,

6. Jan 1, 2016

### BvU

You are welcome !