Сумма и произведение корней
[src] ___________ ___________ ___________ ___________
___ / ___ ___ / ___ ___ / ___ ___ / ___
1 \/ 5 / 5 \/ 5 1 \/ 5 / 5 \/ 5 1 \/ 5 / 5 \/ 5 1 \/ 5 / 5 \/ 5
1 + - - + ----- - I* / - + ----- + - - + ----- + I* / - + ----- + - - - ----- - I* / - - ----- + - - - ----- + I* / - - -----
4 4 \/ 8 8 4 4 \/ 8 8 4 4 \/ 8 8 4 4 \/ 8 8
$$\left(\left(- \frac{\sqrt{5}}{4} - \frac{1}{4} - i \sqrt{\frac{5}{8} - \frac{\sqrt{5}}{8}}\right) + \left(\left(1 + \left(- \frac{1}{4} + \frac{\sqrt{5}}{4} - i \sqrt{\frac{\sqrt{5}}{8} + \frac{5}{8}}\right)\right) + \left(- \frac{1}{4} + \frac{\sqrt{5}}{4} + i \sqrt{\frac{\sqrt{5}}{8} + \frac{5}{8}}\right)\right)\right) + \left(- \frac{\sqrt{5}}{4} - \frac{1}{4} + i \sqrt{\frac{5}{8} - \frac{\sqrt{5}}{8}}\right)$$
/ ___________\ / ___________\ / ___________\ / ___________\
| ___ / ___ | | ___ / ___ | | ___ / ___ | | ___ / ___ |
| 1 \/ 5 / 5 \/ 5 | | 1 \/ 5 / 5 \/ 5 | | 1 \/ 5 / 5 \/ 5 | | 1 \/ 5 / 5 \/ 5 |
|- - + ----- - I* / - + ----- |*|- - + ----- + I* / - + ----- |*|- - - ----- - I* / - - ----- |*|- - - ----- + I* / - - ----- |
\ 4 4 \/ 8 8 / \ 4 4 \/ 8 8 / \ 4 4 \/ 8 8 / \ 4 4 \/ 8 8 /
$$\left(- \frac{1}{4} + \frac{\sqrt{5}}{4} - i \sqrt{\frac{\sqrt{5}}{8} + \frac{5}{8}}\right) \left(- \frac{1}{4} + \frac{\sqrt{5}}{4} + i \sqrt{\frac{\sqrt{5}}{8} + \frac{5}{8}}\right) \left(- \frac{\sqrt{5}}{4} - \frac{1}{4} - i \sqrt{\frac{5}{8} - \frac{\sqrt{5}}{8}}\right) \left(- \frac{\sqrt{5}}{4} - \frac{1}{4} + i \sqrt{\frac{5}{8} - \frac{\sqrt{5}}{8}}\right)$$