If $f:R \to R$ be defined by $f(x) = 3{x^2} - 5$ and $g:R \to R$ by $g(x) = \frac{x}{{{x^2} + 1}}$.

Then, gof is

It is given that,, $f(x) = 3{x^2} - 5$ and $g(x) = \frac{x}{{{x^2} + 1}}$

$gof = g\{ f(x)\} = g\left( {3{x^2} - 5} \right)$
$= \frac{{3{x^2} - 5}}{{{{\left( {3{x^2} - 5} \right)}^2} + 1}} = \frac{{3{x^2} - 5}}{{9{x^4} - 30{x^2} + 25 + 1}}$

$= \frac{{3{x^2} - 5}}{{9{x^4} - 30{x^2} + 26}}$