14 terms

# Chapter 4: Graphing Linear Equations and Functions

Key vocabulary from Chapter 4 of McDougal Littell Algebra I. This chapter covers the graphing of linear equations and functions.
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the four regions into which the coordinate plane is divided by the x-axis and the y-axis
standard form of a linear equation
Ax + By = C, where A, B, and C are real numbers and A and B are BOTH not zero
linear function
the equation Ax + By = C is a ___, provided B does not equal zero
x-intercept
the x-coordinate of a point where a graph crosses the x-axis
y-intercept
the y-coordinate of a point where a graph crosses the y-axis
slope
the ___ (m) of a nonvertical line is the ratio of the vertical change (the rise) to the horizontal change (the run) between any two points (x1,y1) and (x2,y2) on the line: m = y2 - y1 / x2 - x1
rate of change
a comparison of change in one quantity with a change in another quantity; can be represented by the slope of a line
slope-intercept form
a linear equation written in the from y = mx + b where m is the slope and b is the y-intercept of the equation's graph
parallel
two lines in the same plane that do not intersect are ___ lines
direct variation
the relationship of two variables x and y if there is a nonzero number a, such that y = ax; if y = ax, then y is said to vary directly with x
constant of variation
the nonzero constant a in a direct variation equation y = ax or in an inverse equation y = a/x
function notation
a way to name a function using the symbol f(x) instead of y; the symbol f(x) is read as "the value of f at x" or as "f of x"
family of functions
a group of functions with similar characteristics
parent linear function
the function f(x) = x, which is the most basic function in the family of linear functions