Consider a Cauchy-Euler equation x^2y''- xy' +y =x^3 for
x>0.
a) Rewrite the equation as constant- coefficeint equation by
substituting x = e^t.
b) Solve it when x(1)=0, x'(1)=1.
For the following differential equation
y'' + 9y = sec3x,
(a) Find the general solution yh, for the
corresponding homogeneous ODE.
(b) Use the variation of parameters to find the
particular solution yp.