5. let f:r'>r be a mapping such that f(0,0) = 0. determine which of the following are jointly continuous at (0,0) (a) f(xy) = x,y)= (0,0) xy (b) fxu)= x,y)=(0,0

5. Let f:R'>R be a mapping such that f(0,0) = 0. Determine which of the following are jointly continuous at (0,0) (a) f(xy) = x,y)= (0,0) xy (b) fxu)= x,y)=(0,0) (c) S(x,y)=S1n+y sin if xy#0 otherwise