5.
$$f ( x ) = \left( 9 x ^ { 2 } + d \right) \left( x ^ { 2 } - 8 x + ( 10 d + 1 ) \right)$$
where \(d\) is a positive constant.
- Find the four roots of \(\mathrm { f } ( x )\) giving your answers in terms of \(d\).
Given \(d = 4\)
- Express these four roots in the form \(a + \mathrm { i } b\), where \(a , b \in \mathbb { R }\).
- Show these four roots on a single Argand diagram.
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