# Tagged Questions

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### A question on “The weakened Hilbert 16th problem”

In this question we are interested in the number of limit cycles which appear in the following perturbational system:
\begin{equation}\cases{
x'=y -x^{2}+\epsilon P(x,y) \\
y'=-x+\epsilon Q(x,y) }
...

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### Where are the boundary layers?

I am learning perturbation theory and would like to be able to determine where boundary layers are going to occur just by looking at the differential equation.
Let $n\in\mathbb{N}$ and $p_i(x)$, ...