2. (10 points) Define f : R2 - R by f (20 ) : = if x = (21, 12) + (0, 0) =:0 0 if x = 0. (a) (3 points) Calculate (x) at an arbitrary non-zero point r E R. olx if v = ( 1 , 1 ) 2 X 1 don't see zag muokay. 4 x 3+ 2 x 2 3 (b) (3 points) Calculate the two partial derivatives of f at 0, thereby showing that the Jacobian matrix " (0) exists. de lim f ( x + 2 ) - ff x ) dx = hao Oh How to you divide a number by a veete in (c) (2 points) Prove that f is not continuous at I = 0. *-(0, 0) * 4 + * 3 0 to = 0 (d) (2 points) Prove that f is not differentiable at 0, and explain why this does not contradict the derivative-Jacobian matrix relationship