Question

Factorise: x4 +x2 =1

Answer 1

Answer:

Step-by-step explanation:

Consider x4 + x2 + 1

           = (x4 + 2x2 + 1) – x2

           = [(x2)2 + 2x2 + 1] – x2

           = [x2 + 1]2 – x2

It is in the form of (a2 – b2) = (a + b)(a – b)

Hence [x2 + 1]2 – x2 =  [x2 + 1 + x] [x2 + 1 – x]