Chapter 4.1, Problem 7E

In Problems 7–9, find a synchronous solution of the form A $A\cos \Omega t+B\sin \Omega t$ to the given forced oscillator equation using the method of Example 4 to solve for $\text{A}$ and $\text{B}$.

$y^{″}+2y^{\prime }+4y=5\sin 3t$, $\Omega =3$.