1. The problem statement, all variables and given/known data Reduce to a single term: I really have been spending a wretched time to solve that tan (x/2)*(1+sec x)(1+sec 2x)(1+sec 4x)...................................(1+sec (2^n)x) 2. Relevant equations tan (x/2)=2 tan (x/4) / 1- tan^2 (x/4) can this ever help 1+tan^2=sec^2 3. The attempt at a solution Please help!!!!!!!!!! me to get started