The function \(f : x \mapsto 2x^2 - 8x + 14\) is defined for \(x \in \mathbb{R}\).
(ii) Express \(f(x)\) in the form \(a(x+b)^2 + c\), where \(a, b\) and \(c\) are constants.
(iii) Find the range of \(f\).
The function \(g : x \mapsto 2x^2 - 8x + 14\) is defined for \(x \geq A\).
(iv) Find the smallest value of \(A\) for which \(g\) has an inverse.
(v) For this value of \(A\), find an expression for \(g^{-1}(x)\) in terms of \(x\).