Exercise 1.4.17 (17-18)

Find the domain of each function.

17.
(a)
f ( x ) = 1 e x 2 1 e 1 x 2
(b)
f ( x ) = 1 + x e cos x
18.
(a)
g ( t ) = 1 0 t 100
(b)
g ( t ) = sin ( e t 1 )

Answers

17.
(a)
Since the denominator of a fraction cannot be equal to zero, the domain of the function f is:

{ x 1 e 1 x 2 0 } = { x e 1 x 2 1 } = { x 1 x 2 0 } = { x x 2 1 } = = { x x 1  and  x 1 } = ( , 1 ) ( 1 , 1 ) ( 1 , + ) .

(b)
Since the denominator of a fraction cannot be equal to zero and there are no restrictions for the domain of a natural exponential function, the domain of f is:

{ x e cos x 0 } = { x x } =

18.
(a)
Since the term under the root cannot be smaller than zero, the domain of f is:

{ t 1 0 t 100 0 } = { t 1 0 t 100 } = { t t 2 } = [ 2 , + )

(b)
Since there are no restrictions for the domains of sine and natural exponential functions, the domain of the function g is .
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2023-08-31 07:03
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