Hi guys, I have a question which equation i need to prove: <N> = 1 / exp (E-U)/KT +1 from Zg = 1 + Exp (-E-U)/KT where <N> = kt 9 d (ln Zg) / dU I have <N> = 1 / exp (U-E)/KT +1 is the Zg they have given me incorrect? I find my answer very simliar, is it a printing error? My working just consists of putting in the numbers. <N> = 1/KT. KT . 1 / Zg Thanks.