If and , find and .
G × H = {(7, 5), (7, 4), (7, 2), (8, 5), (8, 4), (8, 2)}
H × G = {(5, 7), (5, 8), (4, 7), (4, 8), (2, 7), (2, 8)}
Explanation
This question tests understanding of Cartesian products. The Cartesian product A × B consists of all ordered pairs (x, y) where x ∈ A and y ∈ B. For G × H, each element of G is paired with every element of H. Since G has 2 elements and H has 3 elements, G × H contains = 6 ordered pairs. Similarly, H × G also has 6 ordered pairs but with elements in reverse order. Note that G × H H × G as ordered pairs (a, b) and (b, a) are different.
Solution Steps
Step 1: For G × H, take each element of G = {7, 8} and pair with each element of H = {5, 4, 2}
Step 2: G × H = {(7, 5), (7, 4), (7, 2), (8, 5), (8, 4), (8, 2)}
Step 3: For H × G, take each element of H = {5, 4, 2} and pair with each element of G = {7, 8}
Step 4: H × G = {(5, 7), (5, 8), (4, 7), (4, 8), (2, 7), (2, 8)}