Piecewise Function

Definition

A piecewise function is a mathematical function that is defined by multiple sub-functions, each applicable to a specific interval or domain. These sub-functions are joined together to create a complete function that can model complex real-world scenarios.

5 Must Know Facts For Your Next Test

1. Piecewise functions are useful for modeling situations with different rules or behaviors in different regions or intervals.
2. The domain of a piecewise function is typically divided into distinct intervals, with each sub-function defined for a specific interval.
3. Piecewise functions can be represented using if-then statements, where the sub-function to be used is determined by the input value.
4. Graphically, a piecewise function is represented by connecting the graphs of its individual sub-functions, creating a composite graph.
5. Piecewise functions can be used to model a wide range of real-world phenomena, such as pricing structures, temperature changes, and the motion of objects with different behaviors in different regions.

Review Questions

• Explain how a piecewise function is constructed and the purpose of dividing the domain into distinct intervals.
  • A piecewise function is constructed by defining multiple sub-functions, each applicable to a specific interval or domain. The domain of the piecewise function is divided into these distinct intervals to allow for different rules or behaviors to be applied in different regions. This allows the function to model complex real-world scenarios more accurately, as the behavior of the function may change depending on the input value. The division of the domain into intervals is crucial for the piecewise function to capture the nuances and variations present in the problem being modeled.
• Describe the graphical representation of a piecewise function and how it differs from the graph of a single, continuous function.
  • The graph of a piecewise function is composed of the graphs of its individual sub-functions, connected together to form a composite graph. Unlike a single, continuous function, where the graph is a smooth curve, the graph of a piecewise function typically consists of multiple line segments, curves, or a combination of both, with each segment corresponding to a different sub-function and interval. The points where the sub-functions meet are called the 'breakpoints' of the piecewise function, and they represent the transitions between the different intervals and sub-functions. This discontinuous nature of the graph is a defining characteristic of piecewise functions, allowing them to model complex real-world phenomena that cannot be accurately represented by a single, continuous function.
• Analyze how piecewise functions can be used to model real-world situations and provide examples of such applications.
  • Piecewise functions are incredibly versatile and can be used to model a wide range of real-world phenomena that exhibit different behaviors or rules in different regions or intervals. For example, piecewise functions can be used to model pricing structures, where the price per unit may change based on the quantity purchased or the type of customer. They can also be used to model temperature changes, where the function may have different sub-functions for different seasons or time of day. Additionally, piecewise functions can be used to model the motion of objects, such as a car accelerating, cruising, and then braking, each with its own set of rules and behaviors. By dividing the domain into distinct intervals and applying the appropriate sub-function to each interval, piecewise functions allow for the accurate representation of complex real-world situations that cannot be captured by a single, continuous function.

Related terms

Domain: The set of input values for which a function is defined.

Interval: A set of consecutive real numbers bounded by two values, including or excluding the endpoints.

Absolute Value Function: A piecewise function that returns the distance between a real number and zero on the number line.