## University Calculus: Early Transcendentals (3rd Edition)

a. Domain : The domain is the set of all $(x,y)$ satisfying $x^2+y^2 \lt 16$ . b. Range: $R: z\geq \dfrac{1}{4}$ c. Level Curves: These are the circles with center at (0,0) having radii $r \lt 4$ d. Boundary point is at the circle $x^2+y^2=9$ e. Open. f. Bounded