math
Piecewise Functions
- Definition: A piecewise function is a function that is defined by multiple sub-functions, each of which applies to a certain interval of the independent variable.
- General Form:
f(x) = \begin{cases}
f1(x) & \text{if } x < a \
f2(x) & \text{if } a \leq x < b \
f_3(x) & \text{if } x \geq b
\end{cases} - Example:
f(x) = \begin{cases}
x^2 & \text{if } x < 0 \
2x + 1 & \text{if } 0 \leq x < 3 \
5 & \text{if } x \geq 3
\end{cases} - Graphing:
- Graph each piece separately and ensure to use open or closed circles to denote whether the endpoints are included in each interval.
Linear Functions
- Definition: A linear function is a function that can be expressed in the form of f(x)=mx+b, where m represents the slope and b the y-intercept.
- Slope (m): The slope of a line indicates its steepness and direction. It is calculated as:
m=x<em>2−x</em>1y<em>2−y</em>1 - Y-Intercept (b): The y-intercept is where the line crosses the y-axis (i.e., when x=0).
- Graphing:
- Start at the y-intercept (b) on the y-axis.
- From there, use the slope (m) to find other points on the line. For example, if the slope is 2, rise 2 units up and run 1 unit to the right to find another point.
Key Differences
- Form: Piecewise functions can contain multiple definitions based on the value of x, whereas linear functions maintain a constant slope throughout their domain.
- Graph Shape: Piecewise functions can appear broken or segmented due to their multiple definitions, while linear functions produce straight lines.
Important Concepts
- Continuity: Check for continuity at the boundaries in piecewise functions.
- Domain and Range: Identify the domain and range for both piecewise and linear functions.