Perpendicular lines

lines with opposite reciprocal slopes of each other

ex. y=2x+2

y=-1/2x+3

ex. y=2x+2

y=-1/2x+3

parallel lines

lines with the same slope

ex. y=3x+3

y=3x-11

ex. y=3x+3

y=3x-11

vertical lines

lines that are straight up and down, undefined slope, x=...

ex. x=5

ex. x=5

horizontal lines

lines that are straight side to side, slope of 0, y=...

ex. y=-3

ex. y=-3

scatter plot

a graph of non-linear data points

best fit line

the line that most clearly approximates the data in a scatter plot

slope intercept form

y=mx+b

m= slope

b=y-intercept

m= slope

b=y-intercept

Point slope form

y-y1 = m(x-x1), where m is the slope and (x1,y1) is the point the line is passing through.

standard form

Ax + By=C, where A, B, and C are not decimals or fractions, where A and B are not both zero, and where A is not a negative.