Question

Which of the following is a polynomial with roots -3, -3i, and 3i ?

A. x^3 + 3x^2 + 9x + 27
B. x^3 - 3x^2 + 9x - 27
C. x^3 + 9x^2 + 9x + 81
D. x^3 - 9x^2 + 9x - 81

Answer 1

Expand the following:\[(x+3)(x+3i)(x-3i).\]

Answer 2

Well how do you expand with the i?

Answer 3

Remember that \(i=\sqrt{-1}\). So, \(i\cdot i=-1\), etc.

Answer 4

Im totally confused..can you just tell me the answer please.