4. The curve \(C\) has the equation \(y = ( x - a ) ^ { 2 }\) where \(a\) is a constant.
Given that
$$\frac { \mathrm { d } y } { \mathrm { dx } } = 2 x - 6 ,$$
- find the value of \(a\),
- describe fully a single transformation that would map \(C\) onto the graph of \(y = x ^ { 2 }\).