Derivation of the Curvature Formula κ = y″/(1+y′²)^(3/2)
From the geometric definition of curvature to κ = y″/(1+y′²)^(3/2), and when it reduces to y″.
Differential-Geometry
From the geometric definition of curvature to κ = y″/(1+y′²)^(3/2), and when it reduces to y″.