How to Form the Set Difference A – B
The set difference, also known as the complement of one set with respect to another, is formed by taking all the elements that are in the first set (A) but not in the second set (B).
- Identify the Sets: Start by identifying the two sets you are working with, A and B.
- Examine Each Element in A: Go through each element in set A.
- Check Against B: For each element in A, check if it is also in B.
- Exclude Common Elements: If an element is in both A and B, exclude it from the set difference.
- Form the Set Difference: The remaining elements in A form the set difference A – B.
For example, if A = {1, 2, 3, 4, 5} and B = {4, 5, 6}, then A – B = {1, 2, 3}.
Example: If A = {a, b, c, d, e} and B = {d, e, f}, then A – B = {a, b, c}.
Example with Complement Notation: If A = {a, b, c, d, e} and B = {d, e, f}, then A’ = A – B = {a, b, c}.