Question

Factor x3 + x2 + x + 1 over the complex numbers.

Answer 1

(x+1)(x+i)(x-i)

Explanation:

x3 + x2 + x + 1

Group factor: x2(x+1) + (x+1)

= (x+1)(x2 + 1) = (x+1)(x+i)(x-i)