Question

x⁴-14x²+1 factorise​

Answer 1

= x4 -2x2 - 16x2 +1

= (x4 + 2x2 +1) -16x2

= {(x2)2 + 2.x2.1 + (1)2} -(4x)2

= (x2 +1)2 - (4x)2

= ( x2+1+4x ) (x2+1 - 4x)