11. Evaluate the limit lim along the 2 different paths: y = x and y =3x . Based on your findings, (x,F) (0,0) + V what can you say about the existence of the limit of this problem? 12. For f (x, y) = ,2 + cos x , find of =? av 13. For sin(xyz)=x+3z + y , and z is a function of x. Find = =? ax 14. For f(x, y) = xsiny+ ysinx + xy , find =? Ox dy