linear equations and graphing

linear relation

a relationship that appears as a straight line when graphed

the two types of data

discreet and continuous

continuous data

infinite numbers you cannot count

discreet data

natural numbers you can count

coordinate plate

a 2d grid with four quadrants and two axis

the four quadrants

(+x,+y) (-x,+y) (-x, -y) (+x, -y)

orgin

the point where the x-axis and y-axis meet

two different axis

x-axis and the y-axis aka horizontal and vertical

the formula for oblique / diagonal lines

y=mx+b or f(x)=mx+b

another name for the x-coordinate

abscissa

another name for y-coordinate

ordinate

formula for finding a slope

m=rise/run

b in y = mx + b means

b = y-intercept, the point where the line crosses the y-axis

independent variable

the variable that stands alone and is always on the x-axis

dependent variable

the variable that depends on the independent variable and is always on the y-axis

what you do with the independent variable

you change it

example: time, hours worked, # of items

what do you with the dependent variable

you measure it from that change

example: cost, temperature and quality

equations you use for horizontal lines

y = constant y = b

(the only variable is y)

equation you use for vertical lines

x = constant

(the only variable is x)

equation you use for oblique lines

y = mx + b

(you use both x and y variables)

formula we use to find the total in word problems

(base) + (rate of change)(time/# of things)

interpolation

inside the graph

extrapolation

outside the graph