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Inverse and division of complex numbers. Four parts.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "Apresente na forma $a+bi$.
\nEscreva $a$ e $b$ como frações ou inteiros, não como decimais.
", "advice": "A divisão de dois complexos pode ser realizada através da multiplicação do numerador e do denominador pelo conjugado do denominador.
\n
Suponha que \\[ z = \\frac{a+bi}{c+di},\\;\\; c+di \\neq 0\\] então temos:
\\[\\begin{eqnarray*} z&=&\\frac{a+bi}{c+di}\\\\ &=&\\frac{(a+bi)(c-di)}{(c+di)(c-di)}\\\\ &=&\\frac{(ac+bd)+(bc-ad)i}{c^2+d^2}\\\\ &=&\\frac{ac+bd}{c^2+d^2}+\\frac{bc-ad}{c^2+d^2}i \\end{eqnarray*} \\]
Apesar desta fórmula, a melhor maneira de calcular a divisão é lembrar que é necessário multiplicar o numerador e o denominador pelo conjugado.
(a)
\\[\\begin{eqnarray*}\\simplify[std]{{c1}/{z1}} &=&\\simplify[std]{({c1}*{conj(z1)})/({z1}*{conj(z1)})}\\\\ &=&\\simplify[std]{{c1*conj(z1)}/{abs(z1)^2}}\\\\ &=& \\simplify[std]{{c1*re(z1)}/{abs(z1)^2}-{c1*im(z1)}/{abs(z1)^2}*i} \\end{eqnarray*} \\]
(b)
\\[\\begin{eqnarray*}\\simplify[std]{{c2}/{z2}} &=&\\simplify[std]{({c2}*{conj(z2)})/({z2}*{conj(z2)})}\\\\ &=&\\simplify[std]{{c2*conj(z2)}/{abs(z2)^2}}\\\\ &=& \\simplify[std]{{c2*re(z2)}/{abs(z2)^2}-{c2*im(z2)}/{abs(z2)^2}*i} \\end{eqnarray*} \\]
(c)
\\[\\begin{eqnarray*}\\simplify[std]{{z1}/{z3}} &=&\\simplify[std]{({z1}*{conj(z3)})/({z3}*{conj(z3)})}\\\\ &=&\\simplify[std]{{z1*conj(z3)}/{abs(z3)^2}}\\\\ &=& \\simplify[std]{{re(z1*conj(z3))}/{abs(z3)^2}+{im(z1*conj(z3))}/{abs(z3)^2}*i} \\end{eqnarray*} \\]
(d)
\\[\\begin{eqnarray*}\\simplify[std]{{z3}/{z2}} &=&\\simplify[std]{({z3}*{conj(z2)})/({z2}*{conj(z2)})}\\\\ &=&\\simplify[std]{{z3*conj(z2)}/{abs(z2)^2}}\\\\ &=& \\simplify[std]{{re(z3*conj(z2))}/{abs(z2)^2}+{im(z3*conj(z2))}/{abs(z2)^2}*i} \\end{eqnarray*} \\]
$\\displaystyle \\simplify[std]{{c1}/{z1}} = $ [[0]]
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\nNão inclua parêntesis na sua resposta.
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