Please help to solve the nonhomogenious side of this differential equation.
so the equation is y"+4y'+4y=25*sinX
can't solve the equation after putting back of the first and the second derive of the probe function.
And the probe function is: y=A*sinX+B*cosX+C
First derive: y'=A*cosX-B*sinX
Second derive: y"=-A*sinX-B*cosX
If you put it back its gonna be a huge mess(Thinking)