/ /pi\ /pi\\ / 2/pi\ 2/pi\\ / 2/pi\ 2/pi\ /pi\ /pi\\ / /pi\ /2*pi\ /pi\ /2*pi\ /pi\ /2*pi\ /2*pi\ /pi\\ / /pi\ /2*pi\ /pi\ /2*pi\ /2*pi\ /pi\ /pi\ /2*pi\\ / /pi\ /3*pi\ /pi\ /3*pi\ /pi\ /3*pi\ /3*pi\ /pi\\ / /pi\ /3*pi\ /pi\ /3*pi\ /pi\ /3*pi\ /3*pi\ /pi\\
|x + - I*sin|--| - cos|--||*|x + cos |--| + sin |--||*|x + - sin |--| + cos |--| + 2*I*cos|--|*sin|--||*|x + - cos|--|*cos|----| + sin|--|*sin|----| - I*cos|--|*sin|----| - I*cos|----|*sin|--||*|x + - cos|--|*cos|----| - sin|--|*sin|----| - I*cos|----|*sin|--| + I*cos|--|*sin|----||*|x + cos|--|*cos|----| + sin|--|*sin|----| - I*cos|--|*sin|----| + I*cos|----|*sin|--||*|x + - sin|--|*sin|----| + cos|--|*cos|----| + I*cos|--|*sin|----| + I*cos|----|*sin|--||
\ \7 / \7 // \ \7 / \7 // \ \7 / \7 / \7 / \7 // \ \7 / \ 7 / \7 / \ 7 / \7 / \ 7 / \ 7 / \7 // \ \7 / \ 7 / \7 / \ 7 / \ 7 / \7 / \7 / \ 7 // \ \7 / \ 7 / \7 / \ 7 / \7 / \ 7 / \ 7 / \7 // \ \7 / \ 7 / \7 / \ 7 / \7 / \ 7 / \ 7 / \7 //
$$\left(x + \left(\sin^{2}{\left(\frac{\pi}{7} \right)} + \cos^{2}{\left(\frac{\pi}{7} \right)}\right)\right) \left(x + \left(- \cos{\left(\frac{\pi}{7} \right)} - i \sin{\left(\frac{\pi}{7} \right)}\right)\right) \left(x + \left(- \sin^{2}{\left(\frac{\pi}{7} \right)} + \cos^{2}{\left(\frac{\pi}{7} \right)} + 2 i \sin{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{\pi}{7} \right)}\right)\right) \left(x + \left(- \cos{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{2 \pi}{7} \right)} + \sin{\left(\frac{\pi}{7} \right)} \sin{\left(\frac{2 \pi}{7} \right)} - i \sin{\left(\frac{2 \pi}{7} \right)} \cos{\left(\frac{\pi}{7} \right)} - i \sin{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{2 \pi}{7} \right)}\right)\right) \left(x + \left(- \cos{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{2 \pi}{7} \right)} - \sin{\left(\frac{\pi}{7} \right)} \sin{\left(\frac{2 \pi}{7} \right)} - i \sin{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{2 \pi}{7} \right)} + i \sin{\left(\frac{2 \pi}{7} \right)} \cos{\left(\frac{\pi}{7} \right)}\right)\right) \left(x + \left(\cos{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{3 \pi}{7} \right)} + \sin{\left(\frac{\pi}{7} \right)} \sin{\left(\frac{3 \pi}{7} \right)} - i \sin{\left(\frac{3 \pi}{7} \right)} \cos{\left(\frac{\pi}{7} \right)} + i \sin{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{3 \pi}{7} \right)}\right)\right) \left(x + \left(- \sin{\left(\frac{\pi}{7} \right)} \sin{\left(\frac{3 \pi}{7} \right)} + \cos{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{3 \pi}{7} \right)} + i \sin{\left(\frac{\pi}{7} \right)} \cos{\left(\frac{3 \pi}{7} \right)} + i \sin{\left(\frac{3 \pi}{7} \right)} \cos{\left(\frac{\pi}{7} \right)}\right)\right)$$
((((((x - i*sin(pi/7) - cos(pi/7))*(x + cos(pi/7)^2 + sin(pi/7)^2))*(x - sin(pi/7)^2 + cos(pi/7)^2 + 2*i*cos(pi/7)*sin(pi/7)))*(x - cos(pi/7)*cos(2*pi/7) + sin(pi/7)*sin(2*pi/7) - i*cos(pi/7)*sin(2*pi/7) - i*cos(2*pi/7)*sin(pi/7)))*(x - cos(pi/7)*cos(2*pi/7) - sin(pi/7)*sin(2*pi/7) - i*cos(2*pi/7)*sin(pi/7) + i*cos(pi/7)*sin(2*pi/7)))*(x + cos(pi/7)*cos(3*pi/7) + sin(pi/7)*sin(3*pi/7) - i*cos(pi/7)*sin(3*pi/7) + i*cos(3*pi/7)*sin(pi/7)))*(x - sin(pi/7)*sin(3*pi/7) + cos(pi/7)*cos(3*pi/7) + i*cos(pi/7)*sin(3*pi/7) + i*cos(3*pi/7)*sin(pi/7))
/ 2 4 6 3 5\
(1 + x)*\1 + x + x + x - x - x - x /
$$\left(x + 1\right) \left(x^{6} - x^{5} + x^{4} - x^{3} + x^{2} - x + 1\right)$$
(1 + x)*(1 + x^2 + x^4 + x^6 - x - x^3 - x^5)