2.2 The Graph of a Function
October 10, 2008
2.2 The Graph of a Function
Objectives:
• Identify the graph of a function
• Obtain info from a graph
Oct 10­8:19 AM
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2.2 The Graph of a Function
October 10, 2008
Vertical Line Test
If no vertical line crosses a graph in two or more points, the graph represents a function.
Examples:
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2.2 The Graph of a Function
October 10, 2008
Use the graph to answer the following questions:
(­4, 4)
(a) Find f(0)
(1, 4)
(b) Find f(­4)
(c) Is f(1) positive or negative?
(d) For what value(s) of x does f(x) = 0?
(­2, 0) (0, 0)
(4, ­3)
(e) What is the domain?
(f) What is the range?
(g) How many times does y = 2 intersect the graph?
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2.2 The Graph of a Function
October 10, 2008
Determine whether the graph is that of a function by using the vertical line test. If it is use the graph to find:
(a) Its domain and range
(b) The intercepts if any
(c) Any symmetry with respect to the x­axis, the y­axis, or the origin
y
3
4
­2
x
­2
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2.2 The Graph of a Function
October 10, 2008
Answer the following questions about the given function:
f(x) = x + 2
x ­ 6
(a) Is the point (3, 14) on the graph of f?
(b) If x = 4, what is f(x)? What point is on the graph of f?
(c) If f(x) = 2, what is x? What point(s) are on the graph of f?
(d) What is the domain of f?
f(x) = x + 2
x ­ 6
(e) List the x­intercepts, if any, of the graph of f.
(f) List the y­intercept, if there is one, of the graph of f.
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2.2 The Graph of a Function
October 10, 2008
Homework:
2.2 page 75 (10, 11 ­ 21 odd, 24, 27, 28, 40, 42)
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