Exercise 3.3.1: Unions and intersections of sets.

Define the sets A, B, C, and D as follows:

• A = {-3, 0, 1, 4, 17}
• B = {-12, -5, 1, 4, 6}
• C = {x Z: x is odd}
• D = {x Z: x is positive}

For each of the following set expressions, if the corresponding set is finite, express the set using roster notation. Otherwise, indicate that the set is infinite.

(c)

A C

(d)

A (B C)

(e)

A B C