先求各数的平方
(n^2+1)^2=n^4+2n^2+1
(n^2-1)^2=n^4-2n^2+1
(2n)^2=4n^2
再看看是不是符合勾股定理的条件
(n^2-1)^2+(2n)^2=n^4+2n^2+1
=n^2+1)^2
符合
所以,能.