9514 1404 393
Answer:
(a) (x - 1) (x + 1) (x + i) (x - i)
Explanation:
Perhaps you want the fully factored form.
The difference of squares is factored as ...
a² -b² = (a -b)(a +b)
Your expression can be considered to be the difference of squares ...
(x²)² -(1)² = (x² -1)(x² +1)
Each of these factors can be considered to be the difference of squares:
x² -1 = (x -1)(x +1)
x² +1 = x² -(i²) = (x -i)(x +i)
So, the fully factored form is ...
x^4 -1 = (x -1)(x +1)(x -i)(x +i)