The equation of a curve is \(\quad y=2 x^{2}-20 x+37\).

- Express \(y\) in the form \(a(x+b)^{2}+c,\) where \(a, b\) and \(c\) are integers.
- Write down the coordinates of the stationary point on the curve.

A function \(f\) is defined by \(f : x \mapsto 2 x^{2}-20 x+37\) for \(x>k\). Given that the function \(f ^{-1}(x)\) exists,

- write down the least possible value of \(k\),
- sketch the graphs of \(y= f (x)\) and \(y= f ^{-1}(x)\) on the axes provided,
- obtain an expression for \(f ^{-1}\).