Determine the lever surfaces for the the levels - let and

Question

Question 1

Let ρ and Φ be the real and imaginary part of the cylindrical koordinates. Describe the set in the room that is given by:

(a) r ≥ z
(b) φ = Π/2
(c) r = 4
(d) r = 2x
(e) r ≤ ρ + z

Question 2

The temperature at a certain point (x,y,z) in a body is T(x,y,z) = x² + y² + z² + 2x - 2y

Determine the lever surfaces for the the levels 0,1,2,3