Orthogonal projection.
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Prove that $T$ is an orthogonal projection
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Proof that the 2-norm of orthogonal transformation of a matrix is invariant
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Orthogonality Relations Exercise, Brezis' Book Functional Analysis
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Compactness of the set of $n \times n$ orthogonal matrices
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understanding projection matrices
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Complex bilinear transformation.
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Orthogonal parametrization
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What does orthogonal mean in the context of statistics?
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A projection satisfying $\| Px \| \leq \|x\|$ for all $x$ is an orthogonal projection
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Matrix Concentration for Products- Orthogonality Property
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Orthogonality for Binomial Coefficients
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How to find the orthogonal complement of a subspace?
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Find Orthogonal complement
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Proof of an elementary property of Projection Operators
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Finding all inner products on $\mathbb{R}^2$ for which a given linear map is orthogonal
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Linear transformation preserving orthogonality
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Idempotent linear operators are projections