1.1--Graphs and Graphing Utilities
What you should learn: To sketch graphs of equations and find
x-and y-intercepts of graphs of equations.
Why you should learn it: The graph of an equation can help you
see relationships between real-life quantities. For example a
graph can be used to predict future outcomes like the life
expectancy of newborns in 2015 based on current data.
Often a relationship between two quantities is expressed
as an equation in two variables.
EX: y = 7 ­ 3x
What is a solution to this equation?
How many solutions to this equation are there?
The _______ of an equation is the set of all points that
are solutions of the equation.
EX: Determining Solution Points
Determine whether (2,13) and (­1,­3) lie on the graph of y = 10x ­7
EX: Sketching the Graph of an Equation
Sketch y = 7 ­ 3x
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EX: Sketch the graph of y = x2 ­2
What kind of equation is this?
The table-point-plotting technique is easy but it has some
shortcomings. With too few points plotted, you can badly
misrepresent the graph of the equation.
The four plots we plotted could also be points on the given
graphs.
Intercepts of a Graph
Intercept---point at which the graph intersects the xor y-axis.
Is is possible for a graph to have more than one intercept?
No intercepts?
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EX: Finding x­ and y­Intercepts
Find they x­and y­intercepts for the graph of each equation.
HW : WS
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