Graphs

line of best fit

A line on a scatter plot that is close to the data. This line does NOT have to actually go through any of the points. Do NOT just connect the points!

value

A number, usually refers to the y-value of a function

absolute value

Distance from zero, non-negative value

Function (graph)

Every x goes to only one y. A graph passes the vertical line test.

Function (ordered pairs)

Every x goes to only one y. No ordered pair has the same x, but different y's.

exponential (graph)

y = ab^x the variable is the exponent; the base is a number

quadrants

¼ of coordinate plane, numbered counterclockwise with Roman Numerals

ordered pair

(x, y), parentheses are required; same as coordinates

coordinates

(x, y), parentheses are required; same as ordered pair

Function (mapping diagram)

Every x goes to only one y. No x has two arrows coming out of it.

linear (graph)

Graph of a line, could be slant, horizontal or vertical

solve graphically

Graph the equations, label with equations, write down the point(s) of intersection

intersect (graph)

Graphs touch or cross

x-axis

Horizontal axis; equation is y = 0

maximum

Largest value; Can be the vertex of a parabola that extends downward

parallel

Lines with same slope and different y-intercepts

decrease

Numbers get smaller; graph goes down from left to right

independent variable

Often represented as x, the variable graphed on the horizontal axis, the measure that generates the dependent value

dependent variable

Often represented as y, the variable graphed on the vertical axis, the measure that depends on the independent variable

scatter plot

Points graphed on x and y-axis; do NOT connect points

consistent and appropriate scale

Scale marked on x and y-axes (each may be different). Each graph block is worth the same amount. Graph is not too small or too big—just right!

constant rate

Slope is the same between all points

rate of change

Slope; change in y divided by change in x

minimum

Smallest value; Can be the vertex of a parabola that extends upward

solution set

THE ANSWERS!

axis of symmetry (parabola function)

The vertical line through the vertex (or turning point) of a parabola, equation is x = a.

roots

Values that solve the equation; on a graph, the x-intercepts

y-axis

Vertical axis; equation is x = 0

slope

change in y over change in x

quadratic (graph)

parabola