Mathematics
Answer
Above terms can be written as,
x4 + 2x2 - 16x2 + 1
= x4 + 2x2 + 1 - 16x2
= [(x2)2 + 2x2 + 1] - (4x)2
We know that,
(a + b)2 = a2 + 2ab + b2
and
a2 - b2 = (a - b)(a + b)
∴ [(x2)2 + 2x2 + 1] - (4x)2 = (x2 + 1)2 - (4x)2
= (x2 + 1 - 4x)(x2 + 1 + 4x).
Hence, x4 - 14x2 + 1 = (x2 + 4x + 1)(x2 - 4x + 1).