A complete factorisation of x4 + 64 is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. (x2 + 4x + 8)(x2 - 4x + 8)
x4 + 64
Adding and subtracting 16x2, we get,
= x4 + 16x2 + 64 - 16x2
= (x2 + 8)2 - (4x)2
= (x2 + 4x + 8)(x2 - 4x + 8)