# x- and y-coordinates ```1-6 Relations
 Coordinate system - a grid formed by two intersecting lines (horizontal &amp; vertical)
 Coordinate plane - the plane containing the x- and y-axes
 Origin - the point where the axes intersect (0,0)
 Ordered pair - the coordinates (x, y)
 x- and y-coordinates - the x-value and y-value in the ordered pair
 Relation - a set of ordered pairs
 Mapping - illustrates how each element of the domain is paired with the range
 Domain - the x-coordinate in a relation
 Range - the y-coordinate in a relation
 Independent variable - the value that is subject to choice (domain)
 Dependent variable - the value that depends on the independent variable (range)
1-7 Functions
 Function - a relationship between input and output
 Discrete function – data with spaces between possible data values (dots)
 Continuous function – data with NO spaces between data values (solid line)
 Vertical line test – if a vertical line passes through one point on a graph, it is a function
 Function notation – an equation written in the form f(x)
 Nonlinear function – the graph of a function that is not a straight line
1-8 Interpreting Graphs of Functions
 Intercept - the points where the graph intersects an axes
 x-intercept - the x-coordinate of the point that intersect the x-axis
 y-intercept - the y-coordinate of the point that intersect the y-axis
 Line symmetry - A vertical line that divides a figure into equal parts
3-1 Graphing Linear Equations
 Linear equation - an equation when graphed is a straight line
 Standard form – the equation Ax + By = C
 Constant - “C” in the standard form equation
3-2 Solving Linear Equations by Graphing
 Linear function - a function in which the graph is a line
 Parent function - f(x) = x
 Family of graphs - a group of graphs with one or more similar characteristics
 Root - the solution to an equation
 Zeros - the values of x for which f(x) = 0
3-3 Rate of Change of a Linear Function
 Rate of change - a ratio that compares the change between any two points on a line
 Slope -The rate of change between any two points (m)
3-4 Direct Variation
 Direct variation - a relationship between two variables with a constant ratio
 Constant of variation - a constant rate of change (k)
 Constant of proportionality - a constant rate of change (k)
3-5 Arithmetic Sequences and Functions
 Sequence - a set of numbers in a specific order
 Terms of the sequence – the numbers in a sequence
 Arithmetic sequence – a numerical pattern that increases or decreases at a constant rate
 Common difference – the difference between the terms in a sequence
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