1.2.2 Function Notation Key Objectives • Evaluate functions. • Write functions using function notation. Key Terms • An independent variable is the input of a function; a variable whose value determines the value of the output, or dependent variable . • Function notation is the notation used to express the equation of a function. If x is the independent variable and y is the dependent variable, then the function can be written using f ( x ) for y , where f names the function. Some sets of ordered pairs can be described by using an equation. When the set of ordered pairs described by an equation satisfies the definition of a function, the equation can be written in function notation. If x is the function’s input and y is its output, then in function notation f ( x ) replaces y , and f names the function. For example, the function described by the equation y = 5 x + 3 is the same as the function described by f ( x ) = 5 x + 3. And both of these functions are the same as the set of ordered pairs ( x , 5 x + 3). Note that the graph of a function is a picture of the function’s ordered pairs. Example 1 Evaluating Functions To evaluate a function, find the output value(s) that corresponds to a given input value.
48
Made with FlippingBook flipbook maker