Question

Which of the following is a polynomial with roots –2, –2i, and 2i ?



x^3 – 4x^2 + 4x – 16



x^3 + 4x^2 + 4x + 16



x^3 + 2x^2 + 4x + 8


x^3 – 2x^2 + 4x – 8

Answer 1

Its the third answer

Answer 2

u sure? how'd u get it?

Answer 3

mutiply the roots; i equals sqrt(-1) so when you multiply them together you get -1

Answer 4

\[(x+2)(x+2i)(x-2i)\]
\[(x+2)(x-2\sqrt{-1})(x+2\sqrt{-1})\]
\[(x+2)(x^2+2xsqrt{-1}-2x \sqrt{-1}-4(-1))\]
\[(x+2)(x^2+4)\]
\[x^3+2x^2+4x+8\]