Question 733628
Very simply, you want a function composed on three binomial factors in each each of the given roots corresponds to a binomial factor.


Root of -3, (x+3).
Root of 2-i, (x-(2-i)).
Root of 2+i, (x-(2+i)).


Of course, you may want your function in general form completely multiplied, meaning the product of the three factors.  Can you do this?
[Big hint:  {{{(x+3)*(x-(2-i))*(x-(2+i))}}} ].