• 2022-06-04 问题

    Which of the following statement is false? A: Ais an[img=49x19]1803b6abf33899a.png[/img]matrix.[img=66x23]1803b6abfb9f77f.png[/img]is a QR factorization ofA. The columns ofQform an orthonormal basis for the column space ofA. B: If A=QR, where Q has orthonormal columns, then[img=79x27]1803b6ac036f846.png[/img] C: Ahas a QR factorization, then A must be a square matrix. D: Any matrix can have a QR factorization. E: If a matrix A has a QR factorization, then the ranks of A and Q are the same.

    Which of the following statement is false? A: Ais an[img=49x19]1803b6abf33899a.png[/img]matrix.[img=66x23]1803b6abfb9f77f.png[/img]is a QR factorization ofA. The columns ofQform an orthonormal basis for the column space ofA. B: If A=QR, where Q has orthonormal columns, then[img=79x27]1803b6ac036f846.png[/img] C: Ahas a QR factorization, then A must be a square matrix. D: Any matrix can have a QR factorization. E: If a matrix A has a QR factorization, then the ranks of A and Q are the same.

  • 2022-06-17 问题

    求下面矩阵的 Cholesky 分解 (다음 행렬의 Cholesky factorization을 구하시오). \begin{bmatrix}<br/>1\ \,\, 3\ \,\, 7\\ <br/>3\ 10\ 26\\ <br/>7\ 26\ 75\\<br/>\end{bmatrix} A: \(U=\begin{bmatrix}<br/>1\ 3\ 7\\ <br/>0\ 1\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) B: \(U=\begin{bmatrix}<br/>1\ 2\ 7\\ <br/>0\ 3\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) C: \(U=\begin{bmatrix}<br/>1\ 3\ 7\\ <br/>0\ 2\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) D: \(U=\begin{bmatrix}<br/>1\ 3\ 1\\ <br/>0\ 1\ 5\\ <br/>0\ 0\ 7\\<br/>\end{bmatrix}\) E: \(U=\begin{bmatrix}<br/>1\ 2\ 7\\ <br/>0\ 3\ 1\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\)

    求下面矩阵的 Cholesky 分解 (다음 행렬의 Cholesky factorization을 구하시오). \begin{bmatrix}<br/>1\ \,\, 3\ \,\, 7\\ <br/>3\ 10\ 26\\ <br/>7\ 26\ 75\\<br/>\end{bmatrix} A: \(U=\begin{bmatrix}<br/>1\ 3\ 7\\ <br/>0\ 1\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) B: \(U=\begin{bmatrix}<br/>1\ 2\ 7\\ <br/>0\ 3\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) C: \(U=\begin{bmatrix}<br/>1\ 3\ 7\\ <br/>0\ 2\ 5\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\) D: \(U=\begin{bmatrix}<br/>1\ 3\ 1\\ <br/>0\ 1\ 5\\ <br/>0\ 0\ 7\\<br/>\end{bmatrix}\) E: \(U=\begin{bmatrix}<br/>1\ 2\ 7\\ <br/>0\ 3\ 1\\ <br/>0\ 0\ 1\\<br/>\end{bmatrix}\)

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