Question
For a suitably chosen real constant a, let a
function, $f:R - \left\{ { - a} \right\} \to R$ be defined by
$f(x) = {{a - x} \over {a + x}}$. Further suppose that for any real number $x \ne - a$ and $f(x) \ne - a$,
(fof)(x) = x. Then $f\left( { - {1 \over 2}} \right)$ is equal to :
function, $f:R - \left\{ { - a} \right\} \to R$ be defined by
$f(x) = {{a - x} \over {a + x}}$. Further suppose that for any real number $x \ne - a$ and $f(x) \ne - a$,
(fof)(x) = x. Then $f\left( { - {1 \over 2}} \right)$ is equal to :