Linear Algebra · Linear algebra
Dot Products & Projections
The dot product as length times length times cosine, orthogonality, cosine similarity in search and embeddings, projecting a vector onto a line or subspace, and least squares as projection.
Step 1 of 5 · Overview30 min read ·
Key idea
Prereqs: Vectors; matrix multiplication. Next: SVD & PCA; regression. Sources: Strang, *Introduction to Linear Algebra* ch. 1 & 4; 3Blue1Brown ch. 9.Next: 1. Dot product