Function Domain Range Rita Korsunsky Relations and Functions

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Function, Domain, Range, Rita Korsunsky

Function, Domain, Range, Rita Korsunsky

Relations and Functions A relation is a connection between 2 sets of numbers. For

Relations and Functions A relation is a connection between 2 sets of numbers. For example, (x, y) The x-values represent the domain, and the y-values represent the range. x is the independent variable and y is the dependent variable.

Functions Function A correspondence that assigns to every element in set D EXACTLY one

Functions Function A correspondence that assigns to every element in set D EXACTLY one element in set R. Set D = domain; Set R = range. A function D R Not a function D R 5 10 6 14 8 23

Vertical Line Test Function Not a function

Vertical Line Test Function Not a function

Representing Relations and Functions When a relation is also a function (passes a vertical

Representing Relations and Functions When a relation is also a function (passes a vertical line test), we often use “special” notation. For example, The mapping would be:

Practice Problems (in class) 1. State the domain and range: {(3, 4) (1, 6)

Practice Problems (in class) 1. State the domain and range: {(3, 4) (1, 6) (2, 6)} Domain: {1, 2, 3} Range: {4, 6} 2. Determine whether this mapping represents a function. no, yes, no 3. Is this a function? 3 and 3 are the same value no

Example 1 Find a rule for the pairings given below. Write your rule in

Example 1 Find a rule for the pairings given below. Write your rule in function notation. If I multiply the x-coordinate by 3, I get the ycoordinate. My rule is: domain range

Example 2 Is it a function? Yes, it passes the vertical line test. Find

Example 2 Is it a function? Yes, it passes the vertical line test. Find the domain and the range of this function

Example 3 Tell whether each graph is the graph of a function. If it

Example 3 Tell whether each graph is the graph of a function. If it is, give the domain and range of the function. 8 Passes the vertical line test. Yes, function. 1 1 -2 -2 5

Example 4 Tell whether each graph is the graph of a function. Give the

Example 4 Tell whether each graph is the graph of a function. Give the domain and range. Does not pass the vertical line test. No, not function.

Example 5 Tell whether each graph is the graph of a function. If it

Example 5 Tell whether each graph is the graph of a function. If it is, give the domain and range of the function. Passes the vertical line test. Yes, function.

Example 6

Example 6

Special Functions You should know what the graphs of each of these 5 special

Special Functions You should know what the graphs of each of these 5 special functions look like.

Special Functions

Special Functions

Greatest integer Function For all real numbers, x, the greatest integer function returns the

Greatest integer Function For all real numbers, x, the greatest integer function returns the largest integer.

Practice Problems 4. For g(x)=2 x-1 find g(3) and g(-2). Graph g(x). g(3) =

Practice Problems 4. For g(x)=2 x-1 find g(3) and g(-2). Graph g(x). g(3) = 5 and g(-2) = -5 5. If h(x)=2 x over the domain {-3, 1, 4}, what is the range? Does –h(x)=h(-x)? Range = {-6, 2, 8}, yes