Prep Swift Even and Odd functions query


In this Question, why is -
image
this option correct? I thought Polynomials can’t have negative powers and by that logic, this shouldn’t be an even function.

Kindly help!

Nothing says that they need to be polynomials though?

Aren’t degrees defined only for polynomials? It’s a little confusing.

There is no indication that they need to be polynomials?

Thanks!