Processing Math: Done
Lösung 3.3:3c
Aus Online Mathematik Brückenkurs 2
(Unterschied zwischen Versionen)
K (Lösning 3.3:3c moved to Solution 3.3:3c: Robot: moved page) |
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- | { | + | If we take the minus sign out in front of the whole expression, |
- | < | + | |
- | {{ | + | |
+ | <math>-\left( z^{2}+2iz-4z-1 \right)</math> | ||
+ | |||
+ | |||
+ | and collect together the first-degree terms, | ||
+ | |||
+ | |||
+ | <math>-\left( z^{2}+\left( -4+2i \right)z-1 \right)</math> | ||
+ | |||
+ | |||
+ | we can then complete the square of the expression inside the outer bracket | ||
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+ | |||
+ | |||
+ | <math>\begin{align} | ||
+ | & -\left( z^{2}+\left( -4+2i \right)z-1 \right)=-\left( \left( z+\frac{-4+2i}{2} \right)^{2}-\left( \frac{-4+2i}{2} \right)^{2}-1 \right) \\ | ||
+ | & =-\left( \left( z-2+i \right)^{2}-\left( -2+i \right)^{2}-1 \right) \\ | ||
+ | & =-\left( \left( z-2+i \right)^{2}-\left( -2 \right)^{2}+4i-i^{2}-1 \right) \\ | ||
+ | & =-\left( \left( z-2+i \right)^{2}-4+4i+1-1 \right) \\ | ||
+ | & =-\left( \left( z-2+i \right)^{2}-4+4i \right) \\ | ||
+ | & =-\left( z-2+i \right)^{2}+4-4i. \\ | ||
+ | \end{align}</math> |
Version vom 08:47, 25. Okt. 2008
If we take the minus sign out in front of the whole expression,
z2+2iz−4z−1
and collect together the first-degree terms,
z2+
−4+2i
z−1
we can then complete the square of the expression inside the outer bracket
z2+
−4+2i
z−1
=−
z+2−4+2i
2−
2−4+2i
2−1
=−
z−2+i
2−
−2+i
2−1
=−
z−2+i
2−
−2
2+4i−i2−1
=−
z−2+i
2−4+4i+1−1
=−
z−2+i
2−4+4i
=−
z−2+i
2+4−4i