(1) On the line below (*), the term after the rightmost "=" should be . You incorrectly left out the brackets.
(2) Part (b) is probably simpler if you start from the original expression for , rather than from (*).
25 Mar 2012, 10:01
Roberto
Joined: 03 Jun 2010, 15:18 Posts: 136
Re: Exercise [19.13]
(1) I attached here the corrected solution, adding the missing brackets and correcting a couple of spelling errors.
(2) Probably the approach you mention would be slightly simpler; however I found esthetically better not to use the explicit expression for *F, even if it is provided by Penrose at page 443, because I never proved it, even if it would be straightforward to do.