Question

Factorise.. y^4 +1/y^4 +1

Answer 1

If you meant:
(y^4 +1)/(y^4 +1)
then
= 1

end of story

Answer 2

Hey, didn't I do this one for you earlier this morning ????
Why are your reposting it again??

https://www.jiskha.com/questions/1827397/a-4-4-4-a-4-1factorise-1-is-not-included-4a-4

Answer 3

don't forget that
y^4 + 1 = y^4 + 2y^2 + 1 - 2y^2
= (y^2+1)^2 - 2y^2
= (y^2+1 + √2 y)(y^2+1 - √2 y)

Though not really relevant here since, as Reiny pointed out, the result is just 1

Answer 4

Which is the answer I had given Shehzad in the earlier post

https://www.jiskha.com/questions/1827397/a-4-4-4-a-4-1factorise-1-is-not-included-4a-4

Don't know why he/she had to repost it.