The question :-
The solution given in textbook :-
My answer :-
I am not able to identify which is right. I thought mine may be wrong due to squaring or reciprocal taking but I don't think it is causing any defect as all the terms are positive.
I have been really confused for 2 days. Any help would be really appreciated.
Source :- JEE Advance 2001
Edit :- Thank god! I now know where my solution is wrong.. it was very interesting!! But please help in finding minima of expression whose maximum we found .
I wasn't able to comment since I don't have enough reputation, so I am adding the answer here. Note how the minimum value of the angles can be 0 degrees and maximum can be 90 degrees, hence the minima of this function will be 0.