Question

What is the polynomial function of lowest degree with lead coefficient 1 and roots i, –2, and 2?

Answer 1

best approach is to set "x" equal to each root.
x = i
x = -2
x = 2

then set each one equal to 0, always square the equations containing "i"

x^2 = i^2 = -1
----> x^2 + 1 = 0
x+2 = 0
x-2 = 0

Finally put all the factors together...
---> (x^2+1)(x+2)(x-2)