1. The problem statement, all variables and given/known data Determine values for beta the constant of proportionality for a semiconductor. 2. Relevant equations Given below. 3. The attempt at a solution Im struggling with line 2 to line 3 of the solution. The problem I'm having is I cant 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.