In: Advanced Math
Solve y^4-4y"=g(t) using variation of parameters.
The general solution of given differential equation y(t) =y_c(t) +y_p(t) where y_c is complementary solution (general solution of homogeneous differential equations) and y_p is particular solution.
y(t) =c1+c2t+c3 e^{-2t}+c4 e^{2t}+1.u1+t.u2+e^{-2t} u3+e^{2t} u4.