9709 P1 - Jun 2009 - Q10
732
The function f is defined by \(f : x \mapsto 2x^2 - 12x + 13\) for \(0 \leq x \leq A\), where \(A\) is a constant.
- Express \(f(x)\) in the form \(a(x+b)^2 + c\), where \(a, b\) and \(c\) are constants.
- State the value of \(A\) for which the graph of \(y = f(x)\) has a line of symmetry.
- When \(A\) has this value, find the range of \(f\).
The function \(g\) is defined by \(g : x \mapsto 2x^2 - 12x + 13\) for \(x \geq 4\).
- Explain why \(g\) has an inverse.
- Obtain an expression, in terms of \(x\), for \(g^{-1}(x)\).
