SM 2. Find the degree of homogeneity, if there is one, for each of the following functions:
(a) $f(x_1, x_2, x_3) = \frac{(x_1 x_2 x_3)^2}{x_1^4 + x_2^4 + x_3^4} \left(\frac{1}{x_1} + \frac{1}{x_2} + \frac{1}{x_3}\right)$
(b) the CES function: $x(v_1, v_2, ..., v_n) = A \left(\delta_1 v_1^{-\rho} + \delta_2 v_2^{-\rho} + ... + \delta_n v_n^{-\rho}\right)^{-\mu/\rho}$