Answer Happy

7x2 - y (1 point) In this problem we show that the function 7x² - y f(x,y) = x² + y does not have a limitas (x,y) → (0,0). (a) Suppose that we consider (x, y) + (0,0) along the curve y = 3x. Find the limit in this case: lim (1327)--(0:0) x² + y (b) Now consider (x, y) + (0,0) along the curve y = 4x?. Find the limit in this case: 7x? - y lim (422-(0,0) x2 + y (c) Note that the results from (a) and (b) indicate that has no limit as (x,y) → (0,0) (be sure you can explain whyo). To show this more generally, consider (x, y) + (0,0) along the curve y = mx" for arbitrary m. Find the limit in this case: 7x? - y lim ()-(0,0) x + y (Be sure that you can explain how this result also indicates that has no limit as (x,y) - (0,0).

Find all the first and second order partial derivatives of f(x, y) = -5 sin(2x + y) - 7 cos(x - y). A. al = fx= B. I = Jy = dy ex c. fx D = 19 - E = Syx = аду Sxy= Byd

(1 point) Let f(x, y) = (х – у). Then df -56(x-y) 6 -168(x+y)15 дхду f дхдудх df дх?ду