Cross Product Calculator

Vector A

Vector B

Understanding Cross Product

What is a Cross Product?

The cross product of two vectors results in a vector that is perpendicular to both input vectors. Its magnitude equals the area of the parallelogram formed by the two vectors.

Definition:

A × B = |A| |B| sin(θ) n

where:

  • |A| and |B| are vector magnitudes
  • θ is the angle between vectors
  • n is the unit vector perpendicular to both A and B

Component Form:

A × B = (AyBz - AzBy)i + (AzBx - AxBz)j + (AxBy - AyBx)k

Properties of Cross Product

Key Properties:

  • Anti-commutative: A × B = -(B × A)
  • Distributive: A × (B + C) = (A × B) + (A × C)
  • Not associative: (A × B) × C ≠ A × (B × C)
  • Scalar multiplication: (kA) × B = k(A × B)

Special Cases:

  • Parallel vectors: A × B = 0
  • Perpendicular vectors: |A × B| = |A| |B|
  • Unit vectors: i × j = k, j × k = i, k × i = j

Geometric Applications

Area Calculations

Area of parallelogram = |A × B|

Area of triangle = ½|A × B|

Normal Vector

The cross product provides a vector perpendicular to a plane

Unit normal = (A × B)/|A × B|

Torque in Physics

τ = r × F

where r is position vector and F is force vector

Angular Momentum

L = r × p

where p is linear momentum

Applications in Different Fields

Computer Graphics

  • Surface normal computation
  • 3D model rendering
  • Camera orientation

Robotics

  • Robot arm orientation
  • Motion planning
  • Collision detection

Engineering

  • Structural analysis
  • Force calculations
  • Moment of force