6Sin²x - 7Sinx - 5 = 0
Sinx = m , - 1 ≤ m ≤ 1
6m² - 7m - 5 = 0
D = (- 7)² - 4 * 6 * (- 5) = 49 + 120 = 169 = 13²
![m_{1} =\frac{7-13}{12}=-\frac{6}{12}=-\frac{1}{2} \\\\m_{2}=\frac{7+13}{12}=\frac{20}{12}=1\frac{2}{3}](https://tex.z-dn.net/?f=m_%7B1%7D+%3D%5Cfrac%7B7-13%7D%7B12%7D%3D-%5Cfrac%7B6%7D%7B12%7D%3D-%5Cfrac%7B1%7D%7B2%7D+%5C%5C%5C%5Cm_%7B2%7D%3D%5Cfrac%7B7%2B13%7D%7B12%7D%3D%5Cfrac%7B20%7D%7B12%7D%3D1%5Cfrac%7B2%7D%7B3%7D)
Корень m₂ - не подходит так как больше единицы.
![Sinx=-\frac{1}{2}\\\\x=(-1)^{n}arcSin(-\frac{1}{2})+\pi n,n\in Z\\\\x=(-1)^{n+1}arcSin\frac{1}{2}+\pi n,n\in Z\\\\x=(-1)^{n+1}\frac{\pi }{6}+\pi n,n\in Z](https://tex.z-dn.net/?f=Sinx%3D-%5Cfrac%7B1%7D%7B2%7D%5C%5C%5C%5Cx%3D%28-1%29%5E%7Bn%7DarcSin%28-%5Cfrac%7B1%7D%7B2%7D%29%2B%5Cpi+n%2Cn%5Cin+Z%5C%5C%5C%5Cx%3D%28-1%29%5E%7Bn%2B1%7DarcSin%5Cfrac%7B1%7D%7B2%7D%2B%5Cpi+n%2Cn%5Cin+Z%5C%5C%5C%5Cx%3D%28-1%29%5E%7Bn%2B1%7D%5Cfrac%7B%5Cpi+%7D%7B6%7D%2B%5Cpi+n%2Cn%5Cin+Z)
Тринадцать дней, включая сегодня, ибо 23*13=299
<span>(15²-14²)²+(8×8×8×8×8×8×8×8×8+2×2×2×2×2×2) =
</span>
![(15-14)(15+14)^2 + (8^9 + 2^6) = 29^2 + (2^{27} + 2^6) = 841 + 2^{33}](https://tex.z-dn.net/?f=%2815-14%29%2815%2B14%29%5E2%20%2B%20%288%5E9%20%2B%202%5E6%29%20%3D%2029%5E2%20%2B%20%282%5E%7B27%7D%20%2B%202%5E6%29%20%3D%20841%20%2B%202%5E%7B33%7D)
(√21-√7+√33-√11)/(2√7+2√11)
(√21-√7+√33-√11)/2(√7+√11)=
1/2(√21-√7+√33-√11)•(√7-√11)/(√7+√11)•(√7-
√11)=1/2(√21•√7-√7•√7+√33•√7-√11•√7-
√21•√11+√7•√11-√33•√11+√11•√11)/(7-11)=
1/2(7√3-7+√(33•7)-√77-√(21•11)+√77-√(33•11)+
11)/(-4)=-1/8•(7√3+√(33•7)-√(21•11)-√(33•11))