Solution
= Solution
The <orthogonality> condition is $v_ju_j=0$, so
$$
\boxed{P_{ij}u_j=u_i-v_i\frac{v_ju_j}{v_kv_k}=u_i.}
$$
Every <vector> in the <orthogonal complement> is fixed by the <orthogonal projection>.
= Solution
The <orthogonality> condition is $v_ju_j=0$, so
$$
\boxed{P_{ij}u_j=u_i-v_i\frac{v_ju_j}{v_kv_k}=u_i.}
$$
Every <vector> in the <orthogonal complement> is fixed by the <orthogonal projection>.