This problem concerns the function (a) Use polar coordinates to describe this f...

This problem concerns the function

(a) Use polar coordinates to describe this function.

(b) Using the polar coordinate description obtained in part (a), give some level curves for this function.

(c) Prepare a rough sketch of the graph of f .

(d) Determine lim_{(x,y)→(0,0)} f (x, y), if it exists.

(e) Is f continuous? Why or why not?