Differential Equations, Studying the Unsolvable (3Blue1Brown)
by Grant Sanderson · 3Blue1Brown
Opening chapter of Grant Sanderson's differential equations series. Uses the pendulum to show why most differential equations have no closed-form solution, introducing state vectors, phase space, and step-by-step numerical integration from an initial condition. Gives the geometric picture, a point moving through phase space under a vector field, that makes the initial condition feel like a starting position rather than an arbitrary constant.
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