2D Vector Explorer

Drag the arrow tips to change vectors. Watch addition, dot product, angle, and projection update in real-time.

Vectors

Drag arrow tips to change vectors.

Properties

Vector a
Vector b
|a|
|b|
Dot product
Angle
a + b

The Math Behind It

Vector Basics

  • A 2D vector a = (aₓ, aᵧ) has magnitude and direction
  • Magnitude: |a| = √(aₓ² + aᵧ²)
  • Direction angle: θ = atan2(aᵧ, aₓ)
  • Unit vector: â = a / |a|
  • Components: aₓ = |a| cosθ, aᵧ = |a| sinθ

Operations

  • Addition: a + b = (aₓ + bₓ, aᵧ + bᵧ)
  • Geometrically: place b's tail at a's tip (parallelogram rule)
  • Dot product: a · b = aₓbₓ + aᵧbᵧ = |a||b| cosθ
  • Dot product = 0 means vectors are perpendicular
  • Angle: θ = arccos(a · b / (|a| |b|))
  • Projection of b onto a: proj = (a · b / |a|²) a