Odd and even function

[haoku]

f(x) is an even function if f(-x) = f(x) for any x in the domain of f.
Now I say that f(x) = x^2 is defined on [-5,10]. Can I say f(x) is an even function?

[neutrino]

deleted

[red_dog]

No, you can't.
An odd or even function must be defined on a symmetric domain.
But [-5,10] is not symmetric.

[HallsofIvy]

Is f(8)= f(-8)?