6. Given that 2 and \(5 + 2 \mathrm { i }\) are roots of the equation
$$x ^ { 3 } - 12 x ^ { 2 } + c x + d = 0 , \quad c , d \in \mathbb { R }$$
- write down the other complex root of the equation.
- Find the value of \(c\) and the value of \(d\).
- Show the three roots of this equation on a single Argand diagram.