How can you guess solutions of parametric resonance equation?

AI Thread Summary
The discussion centers on a self-learner studying classical mechanics using Landau's book and seeking clarification on parametric resonance. The equation of motion presented is x'' + ω²(1 + h*cos(γt))x = 0, with resonance maximized when γ approaches 2ω. The author questions the assumption of a solution in the form x = a(t)cos(ω + 1/2ε) + b(t)sin(ω + 1/2ε). The inquiry highlights a need for understanding the derivation of this solution form. The conversation suggests that knowledge of differential equations may be relevant to grasping this concept.
Feynmansama
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Hi, first time asking questions in this forum.
I am self-learning classic mechanics this summer using Laudau's book and so far I feel everything is pretty interesting and makes sense for me. But still, I have some questions that needed to be answered. One of them is about the parametric resonance.
The equation of motion is x'' +ω2(1+h*cosγt)*x = 0, and I am told that the resonance reaches its maximum when γ is close to 2ω,i.e. γ = 2ω+ε. To find out the solution for x, the author assumes the solution to be in the form of x = a(t)cos(ω+1/2ε)+b(t)sin(ω+1/2ε), I don't quite understand how the author comes up with this assumption. Really appreciated if someone can help me.
 
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