Question

factories x ^4 +x^2 +1

Answer 1

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]