Functions and Function Notation Notes

FUNCTION

a specific kind of relationship where every input has exactly one output.
(x-values are used ONLY one time. y-values can be used more than once.)

​There are different tests for different ways of communicating functions:

​1. In a sentence, or a table, consider whether any given x value gives multiple y values at a time.

​

​2. In a graph, use the vertical line test. If you can draw a vertical line through two points on the relation, then it is not a function.

​

​3. Solve the equation for y. If there are two possible solutions of y for one given x, then it is not a function.

Objective: Evaluate functions written in function notation.

https://www.youtube.com/watch?v=Kj3Aqov52TY

Function Notation

a specific way to write a relation when it is a function. ​

General Function Notation: f(x)

Said out loud: "f of x"

Example:

y = 4x - 1 is a function. f(x) = 4x - 1

Read as 'f of x' = 4x - 1

• Given the function h

• Substitute 3, a domain value, on both sides of = for k

• Use order of operations (PEMDAS) to simplify

f(x) = y