Question

How do I know when to use the method of undetermined coefficients vs. the variation of parameters?

Answer 1

eq: \[4y \prime \prime-4y \prime-3y = \cos(2x)\] and i am told to use undetermined coefficients. in the next equation im told to use variation of parameters:\[y \prime \prime+y=\sin(x)\]

these seem like very similar eq why are there two seperate methods? how do i know when to use which?