Defining Continuity at the Origin

[shanepitts]

Homework Statement

Can (a), and (b) be made continuous by suitably defining them at (0, 0)? I'm not sure if I answered it properly; especially part (b). Please help.

(a) [x^2+y^2sin(x)]/[x+y]

(b) [x^2ycos(z)]/(x^3+y^2+z^2)

Homework Equations

Taking the limit from different direction[/B]

The Attempt at a Solution

 

[RUber]

For a) set x = 0 and approach zero in the y direction. does the limit exist?
For b) assume they mean the origin, so (0,0,0).