I found this question from a book ..... I dont know the solution neither i can now find the book ) Let the function $f_n(.....f_3(f_2(f_1(x))))$ be an increasing function. If r of the individual functions are decreasing then find the maximum value of $(n-r)r$
I started thinking by taking
derivative of $f_n(....)$ as >0 and $r$ should be even
then I had put conditions on $n$(even & odd) ....but the newer conditions are now leading to nowhere
any inputs will be highly appreciated