I am not sure if you want a function with the roots being
only 2, 4 + i and 4 - i or a function
which has the roots 2, 4 + i and 4 - i.
As there can be an
infinite number of functions that meet the latter condition, I am providing a function
that has only 2, 4 + i and 4 - i as the roots.
f(x) = (x -
2)(x - (4 + i))(x - (4 - i))
=> f(x) = (x - 2)(x - 4
- i)(x - 4 + i)
=> f(x) = (x - 2)((x - 4)^2 -
i^2)
use i^2 = -1
=>
f(x) = (x - 2)((x - 4)^2 + 1)
open the
brackets
=> f(x) = (x - 2)(x^2 + 16 - 8x +
1)
=> f(x) = (x - 2)(x^2 - 8x +
17)
=> f(x) = x^3 - 8x^2 + 17x - 2x^2 + 16x -
34
=> f(x) = x^3 - 10x^2 + 33x -
34
The function with the roots 2, 4 + i and 4
- i is f(x) = x^3 - 10x^2 + 33x - 34
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