The following statements each describe a relationship between two sets A and B in which the given elements are in the set A. Identify the sets A and B precisely in each case. Determine whether or not the relationship defines a function f:A->B.

a. The triangle T is circumscribed by the given circle C.

b. The circle C circumscribes the given triangle T.

c. The area of a given triangle T is A.

d. The pair {p,q} of points in the plane are the foci of a given ellipse E.

My answers:

a. A is the set of circles. B is the set of triangles. Function.

b. A is the set of triangles. B is the set of circles. Function.

c. A is the set of triangles. B is the area. Function.

d. A is the set of ellipses. B is the set of points. Not a function.