A function f, defined for all non-zero real numbers x, satisfies:
f(x) + 4f(1/x) = 3x.
 Find all values of x for which f(x)=f(1/x);
 Find all values of x for which f(x)=f(-x).
(In reply to True story
Now that's funny! I think the problem is better which two pieces, since solving the first easy part can get get you off on the wrong start for the second part.