13 lines Flashcards
what are lines
lines are functions in the form of f(x) = mx + b
define
slope of line =
rise/run = y2 - y1/ x2 - x1
define
x intercepts is
where the graph crosses the x-axis
technique
to find x intercept
set y equal to 0
define
y intercept is
where the the graph crosses y axis
technique
to find y intercept
set x equal to 0
define
all lines can be expressed in what form?
slope intercept form (y = mx + b), where m is the slope and b is the y intercept
technique
if handed a slope and a point instead of a slope and y intercept, use
point slope form
y - y1 = m (x - x1), where (x1, y1) is the given point
define
if the lines have the same slope
the lines are parallel
define
if the product of two lines is -1 (that is, if one slope is the negative reciprocal of the other)
the lines are perpendicular
example
vertical line is
e.g. x = 3
example
horizontal line is
e.g. y = 3
recognizing type of questions: interpreting linear models
interpreting linear model questions are a direct extension of
the chapter of lines
recognizing type of questions: interpreting linear models
you will have to interpret:
the meaning of the numbers in the models within a real world context and apply your understanding of slope and y-intercept to do so
technique: interpreting linear models
do not get tricked:
into choosing an answer that looks right but ultimately doesn’t fit the context set by the given information, such the variables x and y
