Exercise 1.3.57

Use the given graphs of f and g to evaluate each expression, or explain why it is undefined.

(a)
f ( g ( 2 ) )
(b)
g ( f ( 0 ) )
(c)
( f g ) ( 0 )
(d)
( g f ) ( 6 )
(e)
( g g ) ( 2 )
(f)
( f f ) ( 4 )

Answers

(a)
f ( g ( 2 ) ) = f ( 5 ) = 4 .

(b)
g ( f ( 0 ) ) = g ( 0 ) = 3 .

(c)
( f g ) ( 0 ) = f ( g ( 0 ) ) = f ( 3 ) = 0 .

(d)
( g f ) ( b ) = g ( f ( 6 ) ) = g ( 6 ) .

Since 6 does not lie in the domain of g , the above statement is undefined.

(e)
( g g ) ( 2 ) = g ( g ( 2 ) ) = g ( 1 ) = 4 .

(f)
( f f ) ( 4 ) = f ( f ( 4 ) ) = f ( 2 ) = 2 .

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2023-08-24 17:10
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