Question

What is the factored form of the expression?

s^4 – 16

A. (s - 2)^2(s + 2)^2

B. (s - 2)(s + 2)

C. (s - i)(s + i)(s - 2)(s + 2)

D. (s - 2i)(s + 2i)(s - 2)(s + 2)

A, B, C, or D? Please explain (:

Answer 1

s^2 - 16
= s^2 - 4^2
again the same formula a^2 -b^2
(s-4) (s+4)

Answer 2

because s-4 is again (s+2)(s-2)

Answer 3

\[\huge a^2 - b^2 = (a +b)(a-b)\]

Answer 4

sorry answer is "D"
(s - 2i)(s + 2i) =(s+4)

Answer 5

\(\large s^4-16=(s^2)^2-4^2=(s^2-4)(s^2+4) \)
that first factor is factorable using difference of squares.
that second one is factorable involving "sum of squares"

Answer 6

Thanks a lot guys (: