Cross Product Calculator

Calculate the cross product of two 3D vectors with step-by-step solutions

Calculate Cross Product

Vector A = (ax, ay, az)

Vector A: (2, 3, 7)
Magnitude |A|: 7.874008

Vector B = (bx, by, bz)

Vector B: (1, 2, 4)
Magnitude |B|: 4.582576

Cross Product Results

(-2.000, -1.000, 1.000)
A × B (Cross Product)
2.449490
|A × B| (Magnitude)
3.89°
Angle Between Vectors
(-0.816497, -0.408248, 0.408248)
Unit Vector Direction

Step-by-Step Calculation

Formula: A × B = (a₂b₃ - a₃b₂, a₃b₁ - a₁b₃, a₁b₂ - a₂b₁)

1. x-component: (3)(4) - (7)(2) = 12.000 - 14.000 = -2.000

2. y-component: (7)(1) - (2)(4) = 7.000 - 8.000 = -1.000

3. z-component: (2)(2) - (3)(1) = 4.000 - 3.000 = 1.000

4. Magnitude: √(-2.000² + -1.000² + 1.000²) = 2.449490

Properties & Verification

• Cross product is perpendicular to both original vectors

• A·(A×B) = 0.000000 ≈ 0 ✓

• B·(A×B) = 0.000000 ≈ 0 ✓

• |A×B| = |A| × |B| × sin(θ) = 7.874 × 4.583 × sin(3.9°) = 2.449490

🤚 Right-Hand Rule

Point your index finger in the direction of vector A, middle finger in the direction of vector B. Your thumb will point in the direction of A × B. This helps visualize the cross product direction!

Example: 3D Vector Cross Product

Given Vectors

Vector A: (2, 3, 7)

Vector B: (1, 2, 4)

Goal: Find A × B (cross product)

Step-by-Step Solution

Using formula: A × B = (a₂b₃ - a₃b₂, a₃b₁ - a₁b₃, a₁b₂ - a₂b₁)

1. x-component: (3)(4) - (7)(2) = 12 - 14 = -2

2. y-component: (7)(1) - (2)(4) = 7 - 8 = -1

3. z-component: (2)(2) - (3)(1) = 4 - 3 = 1

4. Result: A × B = (-2, -1, 1)

5. Magnitude: |A × B| = √((-2)² + (-1)² + 1²) = √6 ≈ 2.449

Cross Product Properties

Anti-Commutative

A × B = -(B × A)

Distributive

A × (B + C) = A × B + A × C

Scalar Multiplication

k(A × B) = (kA) × B = A × (kB)

Parallel Vectors

A × A = 0 (zero vector)

Key Formulas

Component Form

A × B = (a₂b₃-a₃b₂, a₃b₁-a₁b₃, a₁b₂-a₂b₁)

Magnitude

|A × B| = |A| × |B| × sin(θ)

Geometric Meaning

Area of parallelogram formed by A and B

Direction

Perpendicular to both A and B (right-hand rule)

Understanding Cross Product

What is Cross Product?

The cross product (vector product) is a binary operation on two vectors in 3D space that produces a third vector perpendicular to both original vectors. The magnitude equals the area of the parallelogram formed by the two vectors.

Mathematical Definition

For vectors A = (a₁, a₂, a₃) and B = (b₁, b₂, b₃), the cross product is:

A × B = (a₂b₃ - a₃b₂, a₃b₁ - a₁b₃, a₁b₂ - a₂b₁)

Geometric Interpretation

  • Direction: Perpendicular to both input vectors (right-hand rule)
  • Magnitude: Area of parallelogram formed by the vectors
  • Zero result: When vectors are parallel or antiparallel

Applications

Physics

Torque, angular momentum, magnetic forces

Engineering

Rotational mechanics, computer graphics

Geometry

Surface normals, area calculations

Computer Graphics

3D transformations, lighting calculations

🔍 Key Insight

The cross product only exists in 3D (and 7D) space. In 2D, use the scalar cross product which gives the z-component: a₁b₂ - a₂b₁

⚠️ Important Note

Cross product is not commutative: A × B ≠ B × A. Instead, A × B = -(B × A). Order matters for direction!