Preciso de ajuda urgente !!
Uma das raizes da equaçao 2x3+x2-7x-6=0 é x1=2.Pode-se afirmar que:
a) as outras raizes não são reais
b) as outras raizes são 17 e -19
c) as outras raizes são iguais
d) as outras raizes estão entre -2 e 0
Soluções para a tarefa
Respondido por
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Boa noite Barbara!
Solução!
Veja que temos um polinômio de terceiro grau,o mesmo tem que ter três raízes,para resolver esse exercício o ideal é usar o dispositivo de Briott Ruffini.
![2 x^{3}+ x^{2} -7x-6=0\\\\\\\\\
Sendo~~uma~~ raiz~~x1= 2](https://tex.z-dn.net/?f=2+x%5E%7B3%7D%2B+x%5E%7B2%7D+-7x-6%3D0%5C%5C%5C%5C%5C%5C%5C%5C%5C%0ASendo%7E%7Euma%7E%7E+raiz%7E%7Ex1%3D+2 "2 x^{3}+ x^{2} -7x-6=0\\\\\\\\\
Sendo~~uma~~ raiz~~x1= 2")
![\underline{~~~~~~2|~~~~2~~~~|~~~~1~~~~|~~~~-7~~~~|~~~~~~-6}\\
\underline{~~-1|~~~~2~~~~|~~~~5~~~~|~~~~~~3~~~~~~|~~~0~~~~~~~}\\
\underline{~~~~~~~|~~~~2~~~~|~~~~3~~~~|~~~~~~0~~~~~~|~~~~~~~~~~~~}\\\\\\\
2x3+3=0\\\\\\
2x3=-3\\\\\\
x3= -\dfrac{3}{2}\\\\\\\
x1=2\\\\\
x2=-1\\\\\
x3=-\dfrac{3}{2}](https://tex.z-dn.net/?f=%5Cunderline%7B%7E%7E%7E%7E%7E%7E2%7C%7E%7E%7E%7E2%7E%7E%7E%7E%7C%7E%7E%7E%7E1%7E%7E%7E%7E%7C%7E%7E%7E%7E-7%7E%7E%7E%7E%7C%7E%7E%7E%7E%7E%7E-6%7D%5C%5C%0A%5Cunderline%7B%7E%7E-1%7C%7E%7E%7E%7E2%7E%7E%7E%7E%7C%7E%7E%7E%7E5%7E%7E%7E%7E%7C%7E%7E%7E%7E%7E%7E3%7E%7E%7E%7E%7E%7E%7C%7E%7E%7E0%7E%7E%7E%7E%7E%7E%7E%7D%5C%5C%0A%5Cunderline%7B%7E%7E%7E%7E%7E%7E%7E%7C%7E%7E%7E%7E2%7E%7E%7E%7E%7C%7E%7E%7E%7E3%7E%7E%7E%7E%7C%7E%7E%7E%7E%7E%7E0%7E%7E%7E%7E%7E%7E%7C%7E%7E%7E%7E%7E%7E%7E%7E%7E%7E%7E%7E%7D%5C%5C%5C%5C%5C%5C%5C%0A2x3%2B3%3D0%5C%5C%5C%5C%5C%5C%0A2x3%3D-3%5C%5C%5C%5C%5C%5C%0Ax3%3D+-%5Cdfrac%7B3%7D%7B2%7D%5C%5C%5C%5C%5C%5C%5C+%0A%0Ax1%3D2%5C%5C%5C%5C%5C%0Ax2%3D-1%5C%5C%5C%5C%5C%0Ax3%3D-%5Cdfrac%7B3%7D%7B2%7D+ "\underline{~~~~~~2|~~~~2~~~~|~~~~1~~~~|~~~~-7~~~~|~~~~~~-6}\\
\underline{~~-1|~~~~2~~~~|~~~~5~~~~|~~~~~~3~~~~~~|~~~0~~~~~~~}\\
\underline{~~~~~~~|~~~~2~~~~|~~~~3~~~~|~~~~~~0~~~~~~|~~~~~~~~~~~~}\\\\\\\
2x3+3=0\\\\\\
2x3=-3\\\\\\
x3= -\dfrac{3}{2}\\\\\\\
x1=2\\\\\
x2=-1\\\\\
x3=-\dfrac{3}{2}")
Boa noite!
Bons estudos!
Solução!
Veja que temos um polinômio de terceiro grau,o mesmo tem que ter três raízes,para resolver esse exercício o ideal é usar o dispositivo de Briott Ruffini.
Boa noite!
Bons estudos!
barbarabelo:
Por que x2=-1?
Bom dia primeiro! Antes da pergunta.Ne?
Consegui entender
Obrigada querido
Ah ,minha mãe já me deu educação mas obg pela ajuda
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