Respostas
respondido por:
1
O determinante da matriz A . B é 0.
A determinante da matriz A deu -8 e a matriz B deu 0
Logo, A.B = -8 . 0 = 0
A determinante da matriz A deu -8 e a matriz B deu 0
Logo, A.B = -8 . 0 = 0
respondido por:
2
Olá
A alternativa correta é letra D) -8
Resolução
![A = \left[\begin{array}{ccc}-1&0&1\\0&2&-2\\\end{array}\right] ~ \cdot~B = \left[\begin{array}{ccc}2&-1\\1&2\\0&1\end{array}\right] \\ \\ \\ \\ AB= \left[\begin{array}{ccc}(-1\cdot2)+(0\cdot1)+(1\cdot0)&~(-1\cdot-1)+(0\cdot2)+(1\cdot1)\\(0\cdot2)+(2\cdot1)+(-2\cdot0)&~(0\cdot-1)+(2\cdot2)+(-2\cdot1)\\\end{array}\right] \\ \\ \\ \\ AB= \left[\begin{array}{ccc}(-2+0+0)&(1+0+1)\\(0+2+0)&(0+4-2)\\\end{array}\right] \\ \\ \\ \boxed{AB= \left[\begin{array}{ccc}-2&2\\2&2\\\end{array}\right] }](https://tex.z-dn.net/?f=++A+%3D+%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-1%26amp%3B0%26amp%3B1%5C%5C0%26amp%3B2%26amp%3B-2%5C%5C%5Cend%7Barray%7D%5Cright%5D+%7E+%5Ccdot%7EB+%3D+++%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%26amp%3B-1%5C%5C1%26amp%3B2%5C%5C0%26amp%3B1%5Cend%7Barray%7D%5Cright%5D++%5C%5C++%5C%5C++%5C%5C++%5C%5C+AB%3D+++%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%28-1%5Ccdot2%29%2B%280%5Ccdot1%29%2B%281%5Ccdot0%29%26amp%3B%7E%28-1%5Ccdot-1%29%2B%280%5Ccdot2%29%2B%281%5Ccdot1%29%5C%5C%280%5Ccdot2%29%2B%282%5Ccdot1%29%2B%28-2%5Ccdot0%29%26amp%3B%7E%280%5Ccdot-1%29%2B%282%5Ccdot2%29%2B%28-2%5Ccdot1%29%5C%5C%5Cend%7Barray%7D%5Cright%5D+++%5C%5C++%5C%5C++%5C%5C++%5C%5C+AB%3D++%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%28-2%2B0%2B0%29%26amp%3B%281%2B0%2B1%29%5C%5C%280%2B2%2B0%29%26amp%3B%280%2B4-2%29%5C%5C%5Cend%7Barray%7D%5Cright%5D++%5C%5C++%5C%5C++%5C%5C+%5Cboxed%7BAB%3D++%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%26amp%3B2%5C%5C2%26amp%3B2%5C%5C%5Cend%7Barray%7D%5Cright%5D+%7D "A = \left[\begin{array}{ccc}-1&0&1\\0&2&-2\\\end{array}\right] ~ \cdot~B = \left[\begin{array}{ccc}2&-1\\1&2\\0&1\end{array}\right] \\ \\ \\ \\ AB= \left[\begin{array}{ccc}(-1\cdot2)+(0\cdot1)+(1\cdot0)&~(-1\cdot-1)+(0\cdot2)+(1\cdot1)\\(0\cdot2)+(2\cdot1)+(-2\cdot0)&~(0\cdot-1)+(2\cdot2)+(-2\cdot1)\\\end{array}\right] \\ \\ \\ \\ AB= \left[\begin{array}{ccc}(-2+0+0)&(1+0+1)\\(0+2+0)&(0+4-2)\\\end{array}\right] \\ \\ \\ \boxed{AB= \left[\begin{array}{ccc}-2&2\\2&2\\\end{array}\right] }")
Agora que encontramos a matriz AB, podemos calcular o determinante
![AB= \left[\begin{array}{ccc}-2&2\\2&2\\\end{array}\right] =(-2\cdot2)-(2\cdot2)=-4-4=\boxed{\boxed{-8}}](https://tex.z-dn.net/?f=AB%3D++%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-2%26amp%3B2%5C%5C2%26amp%3B2%5C%5C%5Cend%7Barray%7D%5Cright%5D+%3D%28-2%5Ccdot2%29-%282%5Ccdot2%29%3D-4-4%3D%5Cboxed%7B%5Cboxed%7B-8%7D%7D "AB= \left[\begin{array}{ccc}-2&2\\2&2\\\end{array}\right] =(-2\cdot2)-(2\cdot2)=-4-4=\boxed{\boxed{-8}}")
Caso não consiga visualizar, tente abrir pelo navegador
http://brainly.com.br/tarefa/7681099
A alternativa correta é letra D) -8
Resolução
Agora que encontramos a matriz AB, podemos calcular o determinante
Caso não consiga visualizar, tente abrir pelo navegador
http://brainly.com.br/tarefa/7681099
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