Functions Purpose 680C6B

1. **Stating the problem:** We want to understand what functions are used for in mathematics. 2. **Definition:** A function is a relation that assigns exactly one output to each input. 3. **Purpose of functions:** Functions are used to model relationships between quantities, describe how one quantity depends on another, and solve problems involving change. 4. **Examples:** Functions can represent physical phenomena like distance over time, economic models like cost depending on production, or abstract relations like mapping numbers to their squares. 5. **Summary:** Functions help us understand and predict behavior in various fields by providing a clear rule connecting inputs to outputs.