Use the integrating factor method to find y solution of the initial value problem y$=2$y$+4$cos$(4$t$),$y$(0)=45.$ Jse the integrating factor method to find y solution of the initial value problem y$^\text{'}=2$ y$+4$ cos $(4$ t$),$ y$(0)=-4/5($a$)$ Find an integrating factor $\backslash$mu $.$ If you leave an arbitrary constant, denote it as c$.\backslash$mu $($t$)($b$)$ Find all solutions y of the differential equation above. Again denote by c any arbitrary integration constant. y$($t$)=($c$)$ Find the only solution of the initial value problem above. y$($t$)=$