Applications Of Discrete Mathematics
7/8/2014
Phase 1 Discussion Board 2 To describe the notion of union and intersection we must first start with a set. A set can be numbers, objects, people etc. When you have sets of things, they can be combined to create a union or have elements in common. For example, if a company were looking for an employee within the database system they could search using last names. Say department A has Smith, Jones, Brown, Doe. Department B has Doe, White, Turner, Smith. The union of these sets would be written as follows:
A U B = {Jones, Brown, Doe, Smith, White, Turner}
The sets intersect with the two names in common, Doe and Smith. That would be written as:
A n B= {Doe, Smith} The logical “and” and the logical “or” are important for database retrieval and flowcharts to help the system or reader to understand which way they need to go to seek out the information requested. Simple and compound statements help understand this notion. To help understand this let’s refer back to the original example. If the person searching the company database wanted to find a specific employee they would search for the last name and maybe first initial. This would take the search from a simple statement to a compound statement. The database would then need to search for the last name first and when it found the right name, Smith, it would then need to search for the first initial J.