If $f({x_1}) - f({x_2}) = f\left( {\frac{{{x_1} - {x_2}}}{{1 - {x_1}{x_2}}}} \right)$ for ${x_1},{x_2} \in [ - 1,\,1]$, then $f(x)$ is
$\log \frac{{(1 - x)}}{{(1 + x)}}$
${\tan ^{ - 1}}\frac{{(1 - x)}}{{(1 + x)}}$
$\log \frac{{(1 + x)}}{{(1 - x)}}$
all of these
If $f(x) = \frac{x}{{x - 1}}$, then $\frac{{f(a)}}{{f(a + 1)}} = $
Let $f(x) = sin\,x,\,\,g(x) = x.$
Statement $1:$ $f(x)\, \le \,g\,(x)$ for $x$ in $(0,\infty )$
Statement $2:$ $f(x)\, \le \,1$ for $(x)$ in $(0,\infty )$ but $g(x)\,\to \infty$ as $x\,\to \infty$
For a suitably chosen real constant $a$, let a function, $f: R-\{-a\} \rightarrow R$ be defined by $f(x)=\frac{a-x}{a+x} .$ Further suppose that for any real number $x \neq- a$ and $f( x ) \neq- a ,( fof )( x )= x .$ Then $f\left(-\frac{1}{2}\right)$ is equal to
If $a, b$ be two fixed positive integers such that $f(a + x) = b + {[{b^3} + 1 - 3{b^2}f(x) + 3b{\{ f(x)\} ^2} - {\{ f(x)\} ^3}]^{\frac{1}{3}}}$ for all real $x$, then $f(x)$ is a periodic function with period
Domain of the function $f(x) = {\sin ^{ - 1}}(1 + 3x + 2{x^2})$ is