Orthogonal Projection onto the Affine set $ \left\{ x \mid A x = b \right\} $
63465
Orthogonal Projection of $ z $ onto the Affine set $ \left\{ x \mid A x = b \right\} $
9138
Projection of a point onto a simple convex polytope
69497
Show that the set of all $n \times n$ orthogonal matrices, $O(n)$, is a compact subset of $\mbox{GL} (n,\mathbb R)$
94844
Unitary map between sets of vectors
58988
Composition of convex function and affine function
141015
Proof of orthogonal matrix
49087
Show that a norm on an inner product space satisfies parallelogram law.
5506
Perturbation property of Orthonormal basis for Hilbert space
153634
A statment about the equivalence between the Axiom of Choice and the surjectivity of the projections.
86110
Proximal Operator Fixed Point Property for Matrices
113326
Proving orthogonality of vectors in a complex vector space
90584
Show set of affine transformations is a group
64861
Intersection of open affines can be covered by open sets distinguished in *both*affines
97994
Orthogonality Relations Exercise, Brezis' Book Functional Analysis
37985
Show that $|x|^2 = |y|^2$ with $A$ orthogonal and $Ax = \cos (θ)x − \sin (θ)y$, $Ay = \sin (θ)x + \cos (θ) y$
143869
Showing that the norm of the canonical projection $X\to X/M$ is $1$
1865
Sub-determinants of an orthogonal matrix