9709 P11 - Jun 2013 - Q8
761
(i) Express \(2x^2 - 12x + 13\) in the form \(a(x + b)^2 + c\), where \(a, b\) and \(c\) are constants.
(ii) The function \(f\) is defined by \(f(x) = 2x^2 - 12x + 13\) for \(x \geq k\), where \(k\) is a constant. It is given that \(f\) is a one-one function. State the smallest possible value of \(k\).
The value of \(k\) is now given to be 7.
(iii) Find the range of \(f\).
(iv) Find an expression for \(f^{-1}(x)\) and state the domain of \(f^{-1}\).
