It has to be solved by using convolution theorem :

i try to separate them into 3 parts :

1/s , 1/s^2 , 1/(s-3) but failed to get the correct answer.

May i know the correct way to solve this question ?

Thank a lots for the reply.

2. Originally Posted by Zachary
It has to be solved by using convolution theorem :

i try to separate them into 3 parts :

1/s , 1/(s-3) , 1/(s-3) but failed to get the correct answer.

May i know the correct way to solve this question ?

Thank a lots for the reply.
When doing partial fractions, you should have
$\frac{A}{s}+\frac{B}{s^2}+\frac{C}{s-3}$.

3. but it should be solved by using convolution theorem right ?

4. In order for you to separate that fraction, you have to use partial fractions.

Try combining your 3 fractions into to 1 to see if you obtain $\frac{1}{s^2(s-3)}$

5. Originally Posted by Zachary
It has to be solved by using convolution theorem :

i try to separate them into 3 parts :

1/s , 1/(s-3) , 1/(s-3) but failed to get the correct answer.

May i know the correct way to solve this question ?

Thank a lots for the reply.
Read this: Convolution for Laplace Transform

$h(t) = LT^{-1}\left[\frac{1}{s^2} \right] * LT^{-1}\left[\frac{1}{s-3} \right]$.

If you need more help, please show what you've done and say where you get stuck.