Can you prove statement (c)? (i.e. can you give an example of f(x) and g(x) such that h(x) is even or odd?)
[note: zero is an even integer. An integer z is even if z has the form z = 2n, n an integer. Zero is clearly of this form. However, an interer z is odd if z has the form z = 2n + 1, n an integer. Clearly no such n exists such that 0 = 2n +1, so zero is not an odd integer. The zero function f(x) = 0, however, is both odd and even, since f(-x) = 0 = f(x) and -f(-x) = -0 = 0 = f(x).]