Describe in words the level surfaces of . Think what the intersections of these surfaces with the three coordinate planes look like.

(a) In symbolic form, these level surfaces are given by where is a constant. For what values of are level surfaces defined?

(Give your answer as an interval or list of intervals; for example, if c is less than 1 or greater than or equal to 2, enter (-inf,1),[2,inf).)

(b) Pick a level surface that intersects the -plane. What is your value of ?

Write the equation for the intersection, as an expression set equal to a constant:
=

(c) Pick a level surface that intersects the -plane. What is your value of (which might be different from that you used in (a)?

Write the equation for the intersection, as an expression set equal to a constant:
=

(d) Pick a level surface that intersects the -plane. What is your value of ?

Write the equation for the intersection, as an expression set equal to a constant:
=

You can earn partial credit on this problem.