Formal definition
||x||_2 = sqrt(Σ_i x_i^2)d(x,y) = ||x-y||What breaks if misunderstood
- Nearest-neighbor and clustering behavior becomes unintuitive in high-dim
- Regularization choices (L1 vs L2) get misapplied
||x||_2 = sqrt(Σ_i x_i^2)d(x,y) = ||x-y||