$B\mathrm{.}2-3$ Let $x_1(t)=2cos(3t+1)$ and $x_2(t)=-3cos$

$(3t-2).$

$(a)$ Determine $a_1$ and $b_{1}so$ that $x_1(t)=$

$a_{1}cos(3t)+b_{1}sin(3t).$

$(b)$ Determine $a_2$ and $b_{2}so$ that $x_2(t)=$

$a_{2}cos(3t)+b_{2}sin(3t).$

$(c)$ Determine $C$ and $so$ that $x_1(t)+x_2(t)=$

Ccos$(3t+)0t1x_a(t)=e^{-t}$

$(b)x_b(t)=sin(25t)$

$(c)x_c(t)=e^{-t}sin(25t)$