1. The problem statement, all variables and given/known data Hi, So I have this problem regarding a photovoltaic cell I found part 1 easy and part 2 wasn't actually too bad either but I couldn't finish the calculation. I managed to get to the stage where I have an integral , the problem is that the upper limit is infinity and I'm not really sure how to handle that, the question also mentions that the problem cannot be solved analytically? The full question - http://screencast.com/t/C96Kqs3M [Broken] solution: http://screencast.com/t/szPlkSEAYE6A [Broken] 2. Relevant equations Provided in solution link ( see above) 3. The attempt at a solution So I found a table of standard integrals that matched the stage I got up to and I used the value there and carried on solving as normal but I ended up with the wrong final answer. The value I found for the integral was 2.4 but I think this is the wrong method as it only valid for 0 to infinity?