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Helppppppppppppppppppppp

Helppppppppppppppppppppp-example-1

2 Answers

5 votes
The domain of a composite function
f(g(x)) is, technically speaking, the set of those inputs
x in the domain of
g for which
g(x) is in the domain of
f. What this is really saying, though, is that the domain is for those
x that overlap in both functions, or that are defined for both
f(x) and
g(x). You can write {
x \ | \ D_f
D_g}.

For this specific example, the domain of
f(x) is {all real numbers
x}. The domain of
g(x) is {
x \ | \ x \\eq 13}. These overlap for all
x such that
x \\eq 13, so the domain of
f(g(x)) is {
x \ | \ x \\eq 13}.
User Neuman
by
5.9k points
4 votes
The first thing you should do in this case is to compose both functions:
f (x) = x + 7
g (x) = 1 / (x-13)
Making the composition
f (g (x)) = (1 / (x-13)) + 7
f (g (x)) = (7 (x-13) +1) / (x-13)
Answer:
The domain of the function is:
x other than 13
(option 4)
User Nakhli
by
5.5k points