The dot product and similarity

The dot product multiplies two vectors piece by piece and adds the results: (1, 2) · (3, 4) = 1×3 + 2×4 = 11. It is large when the vectors point the same way, zero when they are at right angles and negative when they point apart. That makes it a quick measure of similarity, and it is the basic operation inside a neuron and inside attention.

Why it matters: Neurons, embeddings and attention all come down to dot products.

Builds on: Vectors

Learn it, then prove it

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