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Category: Matrices and Determinants

Given-matrix-A-a-1-1-1-a-1-1-1-a-If-B-b-A-and-B-is-orthogonal-determine-value-of-a-and-b-

Question Number 115520 by bemath last updated on 26/Sep/20 $${Given}\:{matrix}\:{A}\:=\:\begin{pmatrix}{{a}\:\:\:\mathrm{1}\:\:\:\:\mathrm{1}}\\{\mathrm{1}\:\:\:{a}\:\:\:\:\mathrm{1}}\\{\mathrm{1}\:\:\:\:\mathrm{1}\:\:\:\:{a}}\end{pmatrix}\: \\ $$$${If}\:{B}\:=\:{b}.{A}\:{and}\:{B}\:{is}\:{orthogonal}\: \\ $$$${determine}\:{value}\:{of}\:{a}\:{and}\:{b}. \\ $$ Answered by bobhans last updated on 26/Sep/20 $${B}\:=\:\begin{pmatrix}{{ab}\:\:\:\:{b}\:\:\:\:\:{b}}\\{{b}\:\:\:\:\:\:{ab}\:\:\:\:{b}}\\{{b}\:\:\:\:\:\:{b}\:\:\:\:\:\:{ab}}\end{pmatrix}\:\:\Rightarrow\:\left({ab}\right)^{\mathrm{2}} +{b}^{\mathrm{2}}…

If-determinant-a-a-2-1-a-3-b-b-2-1-b-3-c-c-2-1-c-3-0-a-b-c-a-b-c-

Question Number 115508 by bemath last updated on 26/Sep/20 $${If}\begin{vmatrix}{{a}\:\:\:\:{a}^{\mathrm{2}} \:\:\:\:\:\:\:\mathrm{1}+{a}^{\mathrm{3}} }\\{{b}\:\:\:\:{b}^{\mathrm{2}} \:\:\:\:\:\:\:\mathrm{1}+{b}^{\mathrm{3}} }\\{{c}\:\:\:\:{c}^{\mathrm{2}} \:\:\:\:\:\:\:\mathrm{1}+{c}^{\mathrm{3}} }\end{vmatrix}=\:\mathrm{0} \\ $$$${a}\neq{b}\neq{c}\:\rightarrow\begin{cases}{{a}\:=?}\\{{b}=?\:}\\{{c}=?}\end{cases} \\ $$ Answered by bobhans last updated…

Find-number-of-skew-symmetric-matrices-of-order-3-3-in-which-all-non-diagonal-elements-are-different-and-belong-to-the-set-9-8-7-7-8-9-

Question Number 180855 by srikanth2684 last updated on 18/Nov/22 $${Find}\:{number}\:{of}\:{skew}\:{symmetric} \\ $$$${matrices}\:{of}\:{order}\:\mathrm{3}×\mathrm{3}\:{in}\:{which} \\ $$$${all}\:{non}\:{diagonal}\:{elements}\:{are}\: \\ $$$${different}\:{and}\:{belong}\:{to}\:{the}\: \\ $$$${set}\:\left\{−\mathrm{9},−\mathrm{8},−\mathrm{7},…,\mathrm{7},\mathrm{8},\mathrm{9}\right\}. \\ $$ Terms of Service Privacy Policy…

If-the-product-of-the-matrices-1-1-0-1-1-2-0-1-1-3-0-1-1-k-0-1-1-378-0-1-then-k-

Question Number 114879 by bobhans last updated on 21/Sep/20 $${If}\:{the}\:{product}\:{of}\:{the}\:{matrices}\: \\ $$$$\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{1}}\\{\mathrm{0}\:\:\:\mathrm{1}}\end{pmatrix}\begin{pmatrix}{\mathrm{1}\:\:\:\:\mathrm{2}}\\{\mathrm{0}\:\:\:\:\mathrm{1}}\end{pmatrix}\begin{pmatrix}{\mathrm{1}\:\:\:\:\:\mathrm{3}}\\{\mathrm{0}\:\:\:\:\:\mathrm{1}}\end{pmatrix}…\begin{pmatrix}{\mathrm{1}\:\:\:\:\:{k}}\\{\mathrm{0}\:\:\:\:\:\mathrm{1}}\end{pmatrix}=\begin{pmatrix}{\mathrm{1}\:\:\:\:\mathrm{378}}\\{\mathrm{0}\:\:\:\:\:\:\:\:\mathrm{1}}\end{pmatrix} \\ $$$${then}\:{k}\:=\: \\ $$ Answered by john santu last updated on 21/Sep/20 $$\left({i}\right)\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{1}}\\{\mathrm{0}\:\:\:\mathrm{1}}\end{pmatrix}\begin{pmatrix}{\mathrm{1}\:\:\:\:\mathrm{2}}\\{\mathrm{0}\:\:\:\:\mathrm{1}}\end{pmatrix}=\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{3}}\\{\mathrm{0}\:\:\:\mathrm{1}}\end{pmatrix}…

Given-a-matrix-A-a-b-c-d-satisfies-the-equation-A-2-A-7I-0-where-I-1-0-0-1-Find-the-value-of-trace-of-A-

Question Number 114554 by bemath last updated on 19/Sep/20 $${Given}\:{a}\:{matrix}\:{A}\:=\:\begin{pmatrix}{{a}\:\:\:{b}}\\{{c}\:\:\:{d}}\end{pmatrix}\:{satisfies} \\ $$$${the}\:{equation}\:{A}^{\mathrm{2}} +\lambda{A}+\mathrm{7}{I}\:=\:\mathrm{0} \\ $$$${where}\:{I}=\begin{pmatrix}{\mathrm{1}\:\:\:\mathrm{0}}\\{\mathrm{0}\:\:\:\mathrm{1}}\end{pmatrix}\:.\:{Find}\:{the}\:{value}\:{of}\: \\ $$$${trace}\:{of}\:{A}\: \\ $$ Answered by bobhans last updated on…

Given-matrix-A-1-0-2-3-B-1-3-2-0-and-AX-2B-I-what-the-value-of-det-X-

Question Number 112505 by bemath last updated on 08/Sep/20 $$\mathrm{Given}\:\mathrm{matrix}\:\mathrm{A}=\begin{pmatrix}{\mathrm{1}\:\:\:\:\mathrm{0}}\\{\mathrm{2}\:\:\:\mathrm{3}}\end{pmatrix}\:,\:\mathrm{B}=\begin{pmatrix}{−\mathrm{1}\:\:\:\:\:−\mathrm{3}}\\{\:\:\:\mathrm{2}\:\:\:\:\:\:\:\:\:\mathrm{0}}\end{pmatrix} \\ $$$$\mathrm{and}\:\mathrm{AX}\:+\mathrm{2B}\:=\:\mathrm{I}\:.\:\mathrm{what}\:\mathrm{the}\:\mathrm{value} \\ $$$$\mathrm{of}\:\mathrm{det}\:\left(\mathrm{X}\right)\:? \\ $$ Answered by john santu last updated on 08/Sep/20 $$\Leftrightarrow\:{AX}\:=\:\begin{pmatrix}{\mathrm{1}\:\:\:\:\mathrm{0}}\\{\mathrm{0}\:\:\:\mathrm{1}}\end{pmatrix}\:−\begin{pmatrix}{−\mathrm{2}\:\:\:\:\:−\mathrm{6}}\\{\:\:\:\mathrm{4}\:\:\:\:\:\:\:\:\:\mathrm{0}}\end{pmatrix}…