Undetermined Coefficients:
a) y'' + y' - 2y = x^2
b) y'' + 4y = e^3x
c) y'' + y' - 2y = sin x
d) y" - 4y = xe^x + cos 2x
e) Determine the correct form of a particular solution, do not solve
y" + y = sin x
Use the method of Undetermined Coefficients to find a general
solution of this system X=(x,y)^T
Show the details of your work:
x' = 6 y + 9 t
y' = -6 x + 5
Note answer is: x=A cos 4t + B sin 4t +75/36; y=B cos
6t - A sin 6t -15/6 t