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Dot Product Calculator

Fast & Accurate Scalar Results for Vectors

Dot Product Calculator

Vector Dimension:
3
Vector A
Vector B

What is the Dot Product?

The dot product (also known as scalar product or inner product) is a mathematical operation that takes two equal-length sequences of numbers (usually coordinate vectors) and returns a single number. This operation combines two vectors to produce a scalar quantity.

A · B = |A| × |B| × cos(θ)

Where |A| and |B| are the magnitudes of vectors A and B, and θ is the angle between them.

Algebraic Definition

For two vectors A = (a₁, a₂, ..., aₙ) and B = (b₁, b₂, ..., bₙ), the dot product is calculated as:

A · B = a₁b₁ + a₂b₂ + ... + aₙbₙ

Example Calculation

Let's calculate the dot product of A = (2, 3, 1) and B = (4, -2, 5):

A · B = (2 × 4) + (3 × -2) + (1 × 5) = 8 - 6 + 5 = 7

Properties of the Dot Product

  • Commutative: A · B = B · A
  • Distributive: A · (B + C) = A · B + A · C
  • Scalar Multiplication: (cA) · B = c(A · B) = A · (cB)
  • Orthogonality: If A · B = 0, then A and B are perpendicular (orthogonal)

Applications of Dot Product

The dot product has numerous applications in mathematics, physics, and engineering:

  • Finding the angle between two vectors
  • Projecting one vector onto another
  • Determining if two vectors are perpendicular
  • Calculating work in physics (work = force · displacement)
  • Computer graphics and 3D rendering
  • Machine learning and data analysis