5. The functions \(f\) and \(g\) are defined by
$$\begin{aligned}
& \mathrm { f } ( x ) \equiv x ^ { 2 } - 3 x + 7 , \quad x \in \mathbb { R } ,
& \mathrm {~g} ( x ) \equiv 2 x - 1 , \quad x \in \mathbb { R } .
\end{aligned}$$
- Find the range of f .
- Evaluate \(g f ( - 1 )\).
- Solve the equation
$$\operatorname { fg } ( x ) = 17$$