2.1 Functions & Their Graphs
relation
elation:: a mapping or pairing of x and y values. (set of points)
domain
omain:: the x-values OR input values OR independent variable.
range
ange:: the y-values OR output values OR dependent variables.
function:
unction: a special relation where there is exactly one y-value for each x-value.
coordinate plane
lane:: Cartesian Plane or x-y plane.
ordered pairs
airs:: points in the form (x, y)
x-coordinate : first value in an ordered pair.
y-coordinate
coordinate:: the second value in an ordered pair.
Ex:
Ex Determine whether each is a relation or function.
a.)
b.)
c.)
d.)
variable: the input variable, typically x
independent variable
dependent variable: the output variable, typically y
graph: the collection of all points (x,y) whose coordinates are solutions of the equation
Graph: y = x – 2
f(x) = 2x – 1 ← function notation, read “f of x”.
linear function: y = mx + b
function notation: f(x) = mx + b
** NOTE: f(x) is just another name for y.
Linear vs. Not Linear
f(x) = – x 2 – 3x + 5
when x = – 2
g(x) = 2x + 6
when x = – 2