How do you factor completely n^4 + 2n^2w^2+ w^4n4+2n2w2+w4?
1 Answer
Jan 2, 2016
n^4+2n^2w^2+w^4n4+2n2w2+w4
=(n^2+w^2)^2=(n2+w2)2
=(n-iw)^2(n+iw)^2=(n−iw)2(n+iw)2
Explanation:
n^4+2n^2w^2+w^4n4+2n2w2+w4
=(n^2)^2+2(n^2)(w^2)+(w^2)^2=(n2)2+2(n2)(w2)+(w2)2
=(n^2+w^2)^2=(n2+w2)2
In addition, if we allow Complex coefficients then
The difference of squares identity can be written:
a^2-b^2 = (a-b)(a+b)a2−b2=(a−b)(a+b)
So we find:
n^2+w^2 = n^2 - (iw)^2 = (n-iw)(n+iw)n2+w2=n2−(iw)2=(n−iw)(n+iw)
Hence we can write:
n^4+2n^2w^2+w^4 = (n-iw)^2(n+iw)^2n4+2n2w2+w4=(n−iw)2(n+iw)2