If f(f(x)) = 1 - 1/(x⁴+2x²+2), then find the value of f(0)

Knowing that y = 1 / (x^2+1) is a solution to the functional equation, the only reasonable answer is f(0) = 1. But how would we know that all other solutions (which?) have the same function value at 0 ?

Posted by JLo on 2019-12-22 08:13:07