📋 Formula sheet
All formulas with illustrations — print and hang on the wall!
🔷 Vectors
Vector operations
|⃗v| = √(x² + y²)
Magnitude
⃗a + ⃗b = (a₁+b₁, a₂+b₂)
Addition
k · ⃗v = (kx, ky)
Scalar multiplication
⃗a · ⃗b = a₁b₁ + a₂b₂
Dot product
cos θ = (⃗a·⃗b)/(|⃗a||⃗b|)
Angle between vectors