Functions and their Graphs

Relations A relation is a mapping, or pairing, of input values with output values. The set of input values is called the domain. The set of output values is called the range. A relation as a function provided there is exactly one output for each input. It is NOT a function if at least one input has more than one output

A Relation can be represented by a set of ordered pairs of the form (x,y) Quadrant II X<0, y>0 Quadrant I X>0, y>0 Origin (0,0) Quadrant IV X>0, y<0 Quadrant III X<0, y<0

In an equation, the input variable is called the independent variable. The output variable is called the dependent variable and depends on the value of the input variable. In y=2x-7 ….. X is the independent var. Y is the dependant var. The graph of an equation in 2 variables is the collection of all points (x,y) whose coordinates are solutions of the equation.

Graphing an equation in 2 variables Construct a table of values Graph enough solutions to recognize a pattern Connect the points with a line or curve

Graph: y = x + 1 Step 3: Step2: Step 1 Table of values

Graphing absolute value taking the absolute value of negative number makes it positive. Therefore graphs of absolute look different than linear graphs.

Graphing terms to remember.. Domain and range All values for x and y Y intercept Where it crosses y axis (x=0) X intercept Where it crosses x axis (y=0) Invariant point Point never changes

Construct a table of values Y= 5x +1 Construct a table of values Graph enough solutions to recognize a pattern Connect the points with a line or curve