1. The problem statement, all variables and given/known data What is the steady state solution to the equation 4y''+4y'+17y=202cos3t (*) ? 2. The attempt at a solution The steady state solution is, if I've got it right, only the particular solution. It's got to be on the form Kcos3x+Msin3x. I calculate the derivatives, put into (*) and find it to be 122,19 cos 3t + 210 sin 3t. It's normal to write steady state solutions on the form Ccos(ωt-η). How can I do that?