Your don't even need to posit fe3 and fo2: f(X) = e(X) + o(X) f(-X) = e(X) - o(X) From there you can explicitly solve the system of linear equations to get e

Your don't even need to posit fe3 and fo2: f(X) = e(X) + o(X) f(-X) = e(X) - o(X) From there you can explicitly solve the system of linear equations to get e(X) and o(X)