Question

USe a method of variation of parameters to find the general solution to the systems of differential equations

X'= (-2 5) X + ( tan t )
-1 2 1/(cos t)

Answer 1

x'=x*A+B(t)
x'+x*(-A)=B(t)
x'*e^(-At) +x*(-A)*e^(-At)=B(t)*e^(-At)
(x*e^(-At))'=B(t)*e^(-At)
=>x*e^(-At)=***** ( take integral by part)