How do you factor x^8 - 1/81x8181?

1 Answer
Dec 13, 2015

(x^8 -1/81)= (x^2 -1/3)(x^2 +1/3)(x^4 + 1/9)(x8181)=(x213)(x2+13)(x4+19)

Explanation:

Given x^8 - 1/81x8181

Using difference of square a^2 -b^2 = (a-b)(a+b)a2b2=(ab)(a+b)
=> (x^4)^2 -(1/9)^2(x4)2(19)2

=>(x^4 -1/9)(x^4 +1/9)(x419)(x4+19)

Use the difference of square again...

=> (x^2 -1/3)(x^2 +1/3)(x^4 + 1/9)(x213)(x2+13)(x4+19)