Piecewise Functions

Definition

A piecewise function is a mathematical function that is defined by multiple sub-functions, each valid for a different interval or domain of the independent variable. These sub-functions are stitched together to form the complete function, allowing it to exhibit different behaviors or characteristics across different regions of its domain.

5 Must Know Facts For Your Next Test

1. Piecewise functions are often used to model real-world phenomena that exhibit different behaviors or characteristics in different regions or conditions.
2. The sub-functions that make up a piecewise function can be of any type, including linear, quadratic, exponential, or even more complex functions.
3. The points where the sub-functions meet are called the 'breakpoints' or 'transition points' of the piecewise function.
4. Piecewise functions can be used to represent functions that are not continuous, as the sub-functions may not connect smoothly at the breakpoints.
5. The notation used to define a piecewise function typically involves a series of conditional statements, with each sub-function accompanied by the interval or condition for which it is valid.

Review Questions

• Explain how the concept of a piecewise function relates to the review of functions in section 1.1.
  • Piecewise functions are a type of function that are directly relevant to the review of functions in section 1.1. Functions, in general, are mathematical relationships between independent and dependent variables, and piecewise functions represent a specific way of defining these relationships. The key connection is that piecewise functions allow for the modeling of more complex, real-world phenomena by breaking down the function into multiple, simpler sub-functions, each valid for a different interval or condition. This aligns with the broader understanding of functions and their properties covered in the 1.1 review.
• Describe how the properties of piecewise functions, such as domain, range, and continuity, might differ from those of more traditional, single-formula functions.
  • Piecewise functions can exhibit different properties compared to single-formula functions. For example, the domain of a piecewise function may be a union of multiple intervals, rather than a single, continuous range. Additionally, piecewise functions may not be continuous at the breakpoints, where the sub-functions meet, leading to potential discontinuities in the overall function. The range of a piecewise function can also be more complex, as it may be a combination of the ranges of the individual sub-functions. Understanding these unique properties of piecewise functions is crucial when analyzing their behavior and applying them to model real-world situations.
• Analyze how the ability to define piecewise functions might be useful in the context of the broader review of functions in section 1.1, and identify potential applications or examples where piecewise functions could be advantageous.
  • The concept of piecewise functions is highly valuable within the broader context of the function review in section 1.1 because it allows for the modeling of more complex, real-world phenomena that cannot be adequately represented by a single, continuous function. Piecewise functions enable the representation of functions that exhibit different behaviors or characteristics in different regions of their domain, which is often the case in practical applications. For example, piecewise functions could be used to model the fuel efficiency of a vehicle, where the function would have different sub-functions to account for city driving, highway driving, and idling conditions. Similarly, piecewise functions could be used to model the cost of a product or service, with different sub-functions for different quantity thresholds or customer types. The flexibility and versatility of piecewise functions make them a powerful tool in the analysis and modeling of real-world functions.

Related terms

Domain:

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

Interval: A continuous range of values on the number line, typically denoted using inequality notation.

Step Function: A type of piecewise function that is constant over intervals and has distinct, discontinuous jumps between the intervals.