Lösung 3.4:3
Aus Online Mathematik Brückenkurs 2
(Unterschied zwischen Versionen)
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- | A polynomial equation which has real coefficients always has complex conjugate roots. We can therefore say directly that the equation, in addition to the roots | + | A polynomial equation which has real coefficients always has complex conjugate roots. We can therefore say directly that the equation, in addition to the roots <math>z=2i</math> and <math>z=-1+i</math>, has roots <math>z=\overline{2i}=-2i</math> and <math>z=\overline{-1+i}=-1-i</math>. Because the equation is of degree 4, it does not have more than 4 roots. |
- | <math>z= | + | |
- | and | + | |
- | <math>z=- | + | |
- | <math>z=\overline{2i}=-2i</math> | + | |
- | and | + | |
- | <math>z=\overline{- | + | |
The answer is thus | The answer is thus | ||
- | + | {{Displayed math||<math>z = \left\{\begin{align} | |
- | <math>\left\{ \begin{ | + | &\phantom{+}2i\,,\\[5pt] |
- | 2i | + | &-2i\,,\\[5pt] |
- | -2i | + | &-1+i\,,\\[5pt] |
- | -1+i | + | &-1-i\,\textrm{.} |
- | -1-i | + | \end{align} \right.</math>}} |
- | \end{ | + |
Version vom 13:29, 31. Okt. 2008
A polynomial equation which has real coefficients always has complex conjugate roots. We can therefore say directly that the equation, in addition to the roots \displaystyle z=2i and \displaystyle z=-1+i, has roots \displaystyle z=\overline{2i}=-2i and \displaystyle z=\overline{-1+i}=-1-i. Because the equation is of degree 4, it does not have more than 4 roots.
The answer is thus
\displaystyle z = \left\{\begin{align}
&\phantom{+}2i\,,\\[5pt] &-2i\,,\\[5pt] &-1+i\,,\\[5pt] &-1-i\,\textrm{.} \end{align} \right. |