diff --git a/300s School/301. ME 2016 - Nonlinear Dynamical Systems 1/2024-09-09 Frameworks and Review.md b/300s School/301. ME 2016 - Nonlinear Dynamical Systems 1/2024-09-09 Frameworks and Review.md
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 # Introduction
+Where do nonlinearities come from?
+Well, a couple of places...
+1. Geometric nonlinearities (pendulum)
+2. External fields
+3. Material properties
+So we're stuck with them. But how do we deal with noninearities?