1-z | |1-z|^2 | |||
1--1 = 2 | 4 | |||
\([1+cos(\frac{2\pi}{7})]+isin(\frac{2\pi}{7})\) | \(1+2cos(\frac{2\pi}{7})\) | |||
\([1-cos(\frac{3\pi}{7})]+isin(\frac{3\pi}{7})\) | \(1-2cos(\frac{3\pi}{7})\) | |||
\([1-cos(\frac{\pi}{7})]+isin(\frac{\pi}{7})\) | \(1-2cos(\frac{\pi}{7})\) | |||
\([1-cos(\frac{\pi}{7})]-isin(\frac{\pi}{7})\) | \(1-2cos(\frac{\pi}{7})\) | |||
\([1-cos(\frac{3\pi}{7})]-isin(\frac{3\pi}{7})\) | \(1-2cos(\frac{3\pi}{7})\) | |||
\([1+cos(\frac{2\pi}{7})]-isin(\frac{2\pi}{7})\) | \(1+2cos(\frac{2\pi}{7})\) | |||
\(\displaystyle sum = \frac{1}{4}+\frac{2}{1+2cos\frac{2\pi}{7}}+\frac{2}{1-2cos\frac{3\pi}{7}}+\frac{2}{1-2cos\frac{\pi}{7}}\\ \\~\\\displaystyle sum \approx 8.3478346790362325\)
2/(1+2cos(2pi/7)) = 0.8900837358250465
2/(1-2cos(3pi/7)) = 3.603875471605593
2/(1-2cos(pi/7) = -2.493959207437541
0.25+0.8900837358250465+3.603875471605593+3.603875471605593 = 8.3478346790362325