Let u = 2i + 3j and v = i + j. Calculate Proj_{v} u.
Let u = 2i + 3j and v = i + j. Calculate Proj_{v} u.
\operatorname{Proj}_{\mathbf{v}} \mathbf{u}=(\mathbf{u} \cdot \mathbf{v}) \mathbf{v} /|\mathbf{v}|^{2}=\left[5 /(\sqrt{2})^{2}\right] \mathbf{v}=(5 / 2) \mathrm{i}+(5 / 2) \mathbf{j}. This is illustrated in Figure 5.