Last updated: March 2, 2026 by Dr. David Park

How to Calculate the Dot Product

Formula

The dot product sums the products of corresponding components: a . b = a1*b1 + a2*b2 + a3*b3.

The angle between vectors is found from cos(theta) = (a . b) / (|a| x |b|).

Common use cases:

  • Calculating work done by a force
  • Determining if vectors are perpendicular
  • Projection of one vector onto another

Frequently Asked Questions

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Dr. David Park

Applied Mathematician, PhD Mathematics

David holds a PhD in Applied Mathematics from MIT. He has published research on numerical methods and computational algorithms used in engineering and scientific calculators.

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