Question

Which of the following is a polynomial with roots 4, -2i, and 2i ?
Choose one answer.
a. x3 - 4x2 + 4x - 16
b. x3 + 4x2 + 4x + 16
c. x3 + 2x2 + 4x + 8
d. x3 - 2x2 + 4x - 8

Answer 1

Thanks!

Answer 2

well
x^3+4x^2+4x-16 By grouping
(x^3+4x^2)+(4x-16)
Therefore: x^2(x+4)+4(x-4)=0
so:( X^2+4)(X^2-4)=0
X^2-16=0 so. X^2=16 . So X=+or- 2

Answer 3

& if u tried this method on the other 3 equations i think the answer will be C