Algebra 2 Chapter 2

Relation

a set of ordered pairs

Domain

set of inputs, also called x-coordinates

Range

Set of ouputs, also called y-coordinates

Function

All x-values must be different; y-values don't matter

In a function every vertical line must intersect the graph in

At most one point

Linear Equations : are Degree 1

a) have no operation other than addition, subtraction and multiplication of a variable by a constant
b) variables cannot be multiplied together
c) variables cannot appear in the denominator of a fraction
d) exponents on the variable must be 1

used to find slope when given 2 points (x1,y1) (x2,y2)

m= y2-y1/x2-x1

horizontal line

0 Slope

slope

The steepness of a line on a graph

parallel lines

have the same slope

perpendicular lines

have negative reciprocal slopes

y-intercept

the point where a graph intersects the y-axis

x-intercept

the point where a graph crosses the x-axis

Standard form of a linear equation

Ax+By=C A,B,C are integers

1. x & y must be on the same side

2. x must be positive

3. no fractions or decimals ex) x-y=-3

m =

-A/B

y-intercept

C/B

x-intercept

C/A

Scatterplot

graph that relates 2 sets of data by plotting the data as ordered pairs; a cluster of points

line of best fit (trend line)

"average" line that goes through the middle of the scatter plot

rises to the right

positive correlation

falls to the right

negative correlation

prediction equation

the equation of the line of best fit that makes predictions about data not in your scatter plot; this is your equation of the line in slope-intercept form (y=mx+b)

If lines do not intersect, then they are

Parallel

If lines intersect and form right angles, then they are

perpendicular

Standard Form

Ax+By=C

slope-intercept form

y=mx+b

If < or > , connect the points with a

Dashed Line

If ≤ or ≥ , connect points with a

Solid Line

If > or ≥ , shade _____ the line

Above

If < or ≤ , shade _____ the line

Below

You only change the inequality sign if you divide or multiply both sides by a negative number. Thus, if you divide or multiply both sides by a positive number,the inequality sign will not change.

TRUE