Find the general solution of the equation
e^(3x)y'' + e^(3x)y' + e^(x)y = 1,
given that y1 = cos(e^(-x) ) is a solution of the corresponding
homogeneous equation.
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