MathematicsMedium110×since 2002Q3821For a suitably chosen real constant a, let a function, f:R−{−a}→Rf:R - \left\{ { - a} \right\} \to Rf:R−{−a}→R be defined by f(x)=a−xa+xf(x) = {{a - x} \over {a + x}}f(x)=a+xa−x. Further suppose that for any real number x≠−ax \ne - ax=−a and f(x)≠−af(x) \ne - af(x)=−a, (fof)(x) = x. Then f(−12)f\left( { - {1 \over 2}} \right)f(−21) is equal to :A13{1 \over 3}31B–3C−13- {1 \over 3}−31D3Check answerSkip