16.-Linear-Algebra-by-Kenneth-Hoffman · Problem 8.2.12
Inner Product Spaces
Mathematics — Linear Algebra · orthogonal-projection-adjoint
Problem
Let W be a finite-dimensional subspace of an inner product space V, and let E be the orthogonal projection of V on W. Prove that (Eα∣β)=(α∣Eβ) for all α, β in V.