For the function g defined as follows: x² g(x, y) = x² + y², (x, y) = 0. (x, y) = (0,0). 0, (a) Use the definition of limit to show that lim(x,y)→(0,0) g(x, y) does not exist. = (b) Use the definition of continuity and result from part (a) above to determine whether g is continuous at (0,0)