Consider an LTI system with transfer function

$H(s)=\frac{1}{s(s+4)}$

If the input to the system is $cos(3t)$ and the steady state output is $Asin(3t+\alpha )$ , then the value
of $A$ is

1. $1/30$
2. $1/15$
3. $3/4$
4. $4/3$

edited