Find Two Paths of Approach from Which One Can Conclude

Essay

Find two paths of approach from which one can conclude that the function has no limit as (x, y) approaches (0, 0).
- $\text { Show that } f ( x , y , z ) = x ^ { 2 } y ^ { 5 } z ^ { 5 } \text { is continuous at every point } \left( x _ { 0 } , y _ { 0 } , z _ { 0 } \right) \text {. }$