Chapter 4.7, Problem 5P

In each of Problems 2 through 5, use the method of variation of parameters to find a particular solution using the given fundamental set of solutions $\left\{x_1,x_2\right\}$.

$x\text{'}=\left(\begin{array}{cc}0& 1\\ -1& 0\end{array}\right)x+\left(\begin{array}{l}\cos t\\ -\sin t\end{array}\right)$,

$x_1=\left(\begin{array}{l}\cos t\\ -\sin t\end{array}\right)$,      $x_2=\left(\begin{array}{l}\sin t\\ \cos t\end{array}\right)$