Factorise:x4 – 256 – InterviewSolution

1.	Factorise:x4 – 256
Answer» x⁴ – 256 = (x²)² – (16)² = (x² + 16) (x² – 16) (using a² – b² = (a + b) (a – b)) = (x² + 16) (x² – 4²) = (x² + 16) (x + 4) (x – 4) (using a² – b² = (a + b) (a – b))

Factorise:x4 – 256

Answer»

x⁴ – 256 = (x²)² – (16)²

= (x² + 16) (x² – 16) (using a² – b² = (a + b) (a – b))

= (x² + 16) (x² – 4²)

= (x² + 16) (x + 4) (x – 4) (using a² – b² = (a + b) (a – b))