What is the Laplace transformation of 7d(t-1)?

[bmn123]

hi there

Could someone maybe help me with the following question please

What is the Laplace transformation of 7d(t-1)?
d(x) represents the impulse function.


a. 7es
b. 7e-s
c. 1
d. 7
e. e-7s
f. Nie een van hierdie antwoorde / None of these answers
g. e7s

I thought i should be b) but i'm not shure

 

[rrumpf]

Re: impuls function

The answer is b.

First, the 7 out front stays out front because it is a constant.

Second, a time shift (t-a) comes out as exp(-a*s). Since a=1 here, this is exp(-s).

The overall answer is 7*exp(-s).

-Tip

 

[anoopjose]

Re: impuls function

yes the answer is surely (b)