Piecewise Function

Definition

A piecewise function is a function that is defined by different formulas or expressions over different intervals or domains of the independent variable. These functions are composed of multiple parts, each with its own rule or equation, allowing for greater flexibility in modeling real-world phenomena.

5 Must Know Facts For Your Next Test

1. Piecewise functions are commonly used to model situations where the behavior of a function changes at certain points or within specific intervals.
2. The different formulas or expressions that define a piecewise function are often separated by conditions or logical statements, such as if-then-else statements.
3. Piecewise functions can be used to represent absolute value functions, step functions, and other functions with distinct behaviors in different regions of the domain.
4. Transformations of functions, such as reflections, stretches, and shifts, can be applied to piecewise functions, resulting in new piecewise functions.
5. The continuity of a piecewise function depends on the continuity of the individual pieces and the behavior at the points where the function changes its formula.

Review Questions

• Explain how piecewise functions can be used to model real-world situations in the context of 1.1 Functions and Function Notation.
  • Piecewise functions are particularly useful for modeling real-world situations where the behavior of a function changes based on different conditions or intervals. For example, in 1.1 Functions and Function Notation, piecewise functions can be used to represent the cost of a taxi ride, where the rate per mile may change after a certain distance or the number of passengers. By defining different formulas for different intervals or conditions, piecewise functions can accurately capture the nuances of such situations and provide a more realistic representation of the underlying relationships.
• Describe how transformations of functions, as covered in 1.5 Transformation of Functions, can be applied to piecewise functions.
  • Piecewise functions can undergo various transformations, just like other functions. In the context of 1.5 Transformation of Functions, each individual piece of a piecewise function can be transformed independently, resulting in a new piecewise function. For instance, a piecewise function representing the height of a person as a function of age can be vertically stretched or reflected, with each piece of the function undergoing the same transformation. This allows for the modeling of more complex real-world scenarios where the behavior of a function changes across different intervals or conditions.
• Analyze how the continuity of a piecewise function, as discussed in 12.3 Continuity, can be determined based on the behavior of the individual pieces and the points where the function changes its formula.
  • The continuity of a piecewise function is a crucial consideration, as covered in 12.3 Continuity. To determine the continuity of a piecewise function, one must examine the continuity of each individual piece and the behavior of the function at the points where the formula changes. If all the pieces are continuous and the function values match at the points where the formula changes, then the overall piecewise function is continuous. However, if there are any jumps or breaks in the function at these transition points, the piecewise function will be discontinuous. Understanding the continuity of piecewise functions is essential for analyzing their properties and behavior, particularly in the context of limits and differentiability.

Related terms

Domain:

The set of all possible input values for a function, which determines the range of values the function can take on.

Interval: A set of consecutive real numbers that can be represented by a range, such as $[a, b]$ or $(a, b)$, where $a$ and $b$ are real numbers.

Continuity:

A property of a function where the function has no breaks or jumps in its graph, and the function value at any point is the same regardless of how the point is approached.