Find the fourth-degree polynomial function with zeros 9, − 9, 9i, and − 9i. Write the function in factored form. f(x) =
(Simplify your answer. Type your answer in factored form. Type an expression using x as the variable. Express complex numbers in terms of i. )

Please show work to reach this solution - (x − 9)(x + 9)(x − 9 i )(x + 9 i )