What is a Function?

Solution

each replacement of a variable by a number that results in a true sentence.

Input

The values of the independent variable (x) in a function.

100

Evaluate f() = 115 - | 25 -40 |

7

Evaluate f(-5) = (4/5)x + 11

155

Evaluate f(10) = x^2 + 7x - 15

-4

Evaluate f(2) = 2x^2 + 3x - 18

43

Evaluate f(35) = 50 - (x/5)

32

Evaluate f(7) = | x - 18 | + 21

Function Notation

A method of writing functions. f(x) is the same as y, and is read 'f of x'. It is NOT f multiplied by x. The 'f' is the name of the function and can be any letter except x or y. The 'x' is the input variable.

Relation

A set of ordered pairs

Output

The values of the dependent variable (aka y or f(x)) in a function.

Vertical Line Test

Use to determine if a graph is a function. If vertical line and function intersect at most one time, then it's a function. If there is more than one intersection, then it's not a function.

Function

a relation in which each element in the domain is paired with exactly one element in the range