Which statement best describes how to determine whether f(x) = 9 – 4x2 is an odd function?

For this case we have the following definitions:

A function is even if, for each x in the domain of f, f (- x) = f (x). The even functions have reflective symmetry through the y-axis.

A function is odd if, for each x in the domain of f, f (- x) = - f (x). The odd functions have rotational symmetry of 180º with respect to the origin.

We then have the following function:

Applying the definitions we have:

The function is not odd because it is fulfilled:

Therefore, the function is even.