Factorise:x^4+4
x^4 + 4
= (x^4 + 4x^2 + 4) - 4x^2
= (x^2 + 2)^2 - (2x)^2
= [(x^2 + 2) - 2x][(x^2 + 2) + 2x]
= (x^2 - 2x + 2)(x^2 + 2x + 2)
hope this helped
= (x^4 + 4x^2 + 4) - 4x^2
= (x^2 + 2)^2 - (2x)^2
= [(x^2 + 2) - 2x][(x^2 + 2) + 2x]
= (x^2 - 2x + 2)(x^2 + 2x + 2)
hope this helped