What is the polynomial for the question above

A polynomial of degree n with roots  can be represented as: , where A is a constant (The same "a" that appears outside the parentheses in the field where you will type the polynomial). In this question, the number of roots is 4, because the degree of f(x) is 4. If a polynomial has only real coefficients, the complex roots appear in pairs of conjugates. So, since  is a zero,  is a zero too. Then, we have the 4 zeros. Hence,  will be in the form: