Fuck wtf. I gotta type this up again?!
Any number to the power of an even power is always positive.
A negative numebr to the power of an odd power is negative.
A pos number to the power of an odd number is positive.
Skipping to the last one
f(x) = 1/x^3 -1
f(-x) = 1/ (-x)^3 - 1
= 1/ -x^3 - 1
=- 1/(x^3+1)
-f(x)= - 1 / x^3 - 1
As you can see, f(-x) is neither f(x) or -f(x). Hence it's neither.