How to solve this

Question

F(a) = log(1+a)/(1-a) then f(2a/(1+a²) = ?

Answer 1

f(2a/(1+a^2)= log[(1+2a/(1+a^2))/(1-2a/(1+a^2) ]

 

                    = log[(1+a^2+2a)/(1+a^2-2a)]

 

                    = log[(1+a)^2)/(1-a)^2)]

 

                     =log[(1+a)/(1-a)]^2

 

                     = 2 log[(1+a)/(1-a)]

 

Well,I assume that symbols F & f are same in your question.