1. Relations and Functions, Domain & Range
A RELATION is an equation which establishes the relationship between two variables and helps determine one variable when given the other.
y = x y = -2x + 5
A relation is called a FUNCTION when there is no more than one output for each input.
x=2
The set of possible inputs of a relation is called the DOMAIN, while the set of all possible outputs of a relation is called the RANGE.
f(x)=3x+4
f(2)=10
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2. Functions
A way to determine whether a relation is a function is to use the vertical line test.
Use a pencil or a straightedge to represent a vertical line.
Place the pencil at the left of the graph. Move it to the right across the graph. If, for each value of x in the domain, it passes through no more than one point on the graph, then the graph represents a function.
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3. Functions
Day 98