Answer:
Two expressions are relatively prime if their greatest common divisor is one.
Given the terms: [tex]n^3 + 2n$ and n^4 +3n^2 +1[/tex], [tex]n \in N|\{0\}}[/tex]
[tex]n^3 + 2n=n(n^2+2)\\n^4 +3n^2 +1$ is not factorizable\\[/tex]
Therefore, the greatest common divisor of the two expressions is 1.
Therefore, for all n in the set of natural numbers, (where n cannot be zero.) The two expressions are relatively prime.