9. Consider the following specific CES production function defined on x >0. X2>0: y= f(x1, x2)= [0.3x +0.7x]-1/2

(a) Find an expression for the MRTS, and show that isoquants are strictly convex to the origin.

(b) Use the determinant condition in theorem 11.12 to show that fis quasiconcave.

(c) Show that f is concave.

(d) Show that f is homogeneous, and find its degree of homogeneity.

(e) Show that the following result (from Euler's theorem) applies to f f1x1+f2x2 = kf (x1, x2) where k is the degree of homogeneity of

f.

(f) Use the formula given in definition 11.9 to find the elasticity of sub- stitution between the inputs for this function.