Remember that E(-x) = E(x) for all even functions (and all real numbers for x) and that O(-x) = - O(x) :
So for each let's plug in -x into the resulting equaiton and see what comes out:
1) F(x) = E(x) O(x)
F(-x) = E(-x) O(-x) = E(x) (- O(x)) = - E(x) * O(x) = -F(x), which means that F(x) is
an ODD function
