Parametric, Polar & Vectors · Vector Operations

Vector Projection

projvu=uvv2v\text{proj}_{\vec{v}} \vec{u} = \frac{\vec{u} \cdot \vec{v}}{|\vec{v}|^2} \vec{v}

The projection of u onto v gives the component of u in the direction of v.

Variables

SymbolNameUnit
u1u x-component
u2u y-component
v1v x-component
v2v y-component

Worked examples

Find proj_v u where u = ⟨3, 4⟩ and v = ⟨1, 0⟩.
  1. u · v = 3. |v|² = 1.
  2. proj = (3/1)⟨1, 0⟩ = ⟨3, 0⟩

Answer: ⟨3, 0⟩

Find proj_v u where u = ⟨2, 3⟩ and v = ⟨1, 1⟩.
  1. u · v = 2+3 = 5. |v|² = 2.
  2. proj = (5/2)⟨1, 1⟩ = ⟨5/2, 5/2⟩

Answer: ⟨5/2, 5/2⟩

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