- The functions \(f\) and \(g\) have domains \(( - 1 , \infty )\) and \(( 0 , \infty )\) respectively and are defined by
$$f ( x ) = \cosh x , \quad g ( x ) = x ^ { 2 } - 1$$
- State the domain and range of \(f g\).
- Solve the equation \(f g ( x ) = 3\). Give your answer correct to three decimal places.