Is y=(x+1)(x-3) an odd, even, or neither function?

Question

f(x)=(x+1)(x-3)
= x^2-2x-3
substitute in f(-x)
f(-x)=(-x)^2-2(-x)-3
= x^2+2x-3

Therefore it is neither function?

Answer 1

Neither.
https://www.chilimath.com/lessons/intermediate-algebra/even-and-odd-functions/