Answer
Refer answer below.
Work Step by Step
a. Domain : A set of all points $(x,y)$ lies when $x^2+y^2 =1$
b. Range: Real numbers
c. The level curves are the circles whose center is at (0,0) with radius $r \gt 1$
d. Boundary point lies at the circle $x^2+y^2=1$
e. Open
f. Unbounded
