Question Details

If the Laplace transform of a function 𝒇(𝒕) is given by s + 3 ( s + 1 ) ( s + 2 ) , then 𝒇(𝟎) is

Options

A

0

B

1/2

C

1

D

3/2

Correct Answer :

1

Solution :

The correct option is 1.

To find the value of f(0) from its Laplace transform F(s)=L{f(t)}, we can use the Initial Value Theorem of Laplace transforms.

The Initial Value Theorem states that if a function f(t) and its derivative are Laplace transformable, then:
f ( 0 ) = lim t 0 f ( t ) = lim s s F ( s )

Here, the Laplace transform F(s) is given by:
F ( s ) = s + 3 ( s + 1 ) ( s + 2 )

Now, let's construct the expression sF(s):
s F ( s ) = s s + 3 ( s + 1 ) ( s + 2 ) = s 2 + 3 s s 2 + 3 s + 2

Next, we evaluate the limit of sF(s) as s approaches infinity. To simplify this limit, divide the numerator and the denominator by the highest power of s, which is s2:
lim s s F ( s ) = lim s 1 + 3 s 1 + 3 s + 2 s 2

As s, the terms 3s and 2s2 approach 0:
f ( 0 ) = 1 + 0 1 + 0 + 0 = 1

Thus, the value of f(0) is 1.

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