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Composition of functions
Inverse function
By the end of the lesson you will be able to:
• Understand and use composite functions.
• Understand and use  inverse  functions.
http://www.youtube.com/watch?v=GW3Sq6Ez9zA
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Starter:
With your calculator draw the graph of  y= ex
.
State domain, range and asymptotes of this function.
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Composition of functions
If   and
find in simplest form:
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Given the functions and
find
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x
f(x)
f g
g(f(x))
For  to exist, then  range of f must be
  included in the domain of g.
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Indentity function:
What happens when this function is composed with another
function?
g(x) = 2 x ­ 3
=
=
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Inverse function
x f(x)
f
f ­1
The inverse of a function exists if and only if the function is a
one-to-one function.
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Which of these functions have an inverse?
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Find the inverse of :
draw the graphs of both functions. Draw the
identity function on the same graph.
and
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y = 3x+2
y = x
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The graph of is a reflection of the graph of
about the line y = x
Find the inverse function of
and sketch both graphs.
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Find the inverse function of 
Draw the graphs of both functions.
is a self­inverse function
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Find the inverse function of
for x≠1 and sketch both graphs.

Functions 2 inverse , composite