Semiconductor problem - Rearranging terms.

[rwooduk]

Homework Statement

Determine values for beta the constant of proportionality for a semiconductor.

Homework Equations

Given below.

The Attempt at a Solution

Im struggling with line 2 to line 3 of the solution. The problem I'm having is I can't see where the squared exponential term has gone. I've tried multiplying out beta and collecting terms in terms of the exponential term, but I'm stuck with the squared expontntial term that would be there. Any ideas on what he has done would really help at this point.

 

[RUber]

I don't see any squared exponential. I see exp(k) times exp(-k) which is one.

 

[rwooduk]

I don't see any squared exponential. I see exp(k) times exp(-k) which is one.

Good point. Dont know what I was thinking, thanks very much for your help!