1. The problem states $\sup(1,2) = 2$, which asks us to confirm the supremum (least upper bound) of the set \{1, 2\}. 2. The supremum is the smallest number that is greater than or equal to every element in the set. 3. The set \{1, 2\} contains two numbers, 1 and 2, so we need to find the least upper bound. 4. Since 2 is greater than both 1 and 2, and no smaller number is an upper bound, the supremum is indeed 2. Final answer: $\sup\{1,2\} = 2$