A1 = 8 – В 1 день.
An = 218 – Последний день.
Sn = 4859 – Всего селфи.
Формула:
Sn = (A1 + An) * n / 2
4859 = (8 + 218) * n / 2
4859 = (226 / 2) * n
4859 = 113 * n
n = 43
Ответ: 43 дней.
Sin a=<span>√1-cos^2a=</span><span>√1-55/64=3/8
8*3/8=3</span>
0,0140
если без минут,то вот
![\lim_{n \to \ 1} \frac{2x^2+5x-7}{x^2-1} =\frac{2*1^2+5*1-7}{1^1-1}= \frac{0}{0} \\ \\ \lim_{n \to \ 1} \frac{2x^2+5x-7}{x^2-1} = \lim_{n \to \ 1} \frac{2(x+3,5)(x-1)}{(x-1)(x+1)}= \\ \\ = \lim_{n \to \ 1} \frac{2(x+3,5)}{x+1}=\frac{2*(1+3,5)}{1+1}= \frac{2*4,5}{2} =4,5](https://tex.z-dn.net/?f=%5Clim_%7Bn%20%5Cto%20%5C%201%7D%20%5Cfrac%7B2x%5E2%2B5x-7%7D%7Bx%5E2-1%7D%20%3D%5Cfrac%7B2%2A1%5E2%2B5%2A1-7%7D%7B1%5E1-1%7D%3D%20%5Cfrac%7B0%7D%7B0%7D%20%5C%5C%20%5C%5C%20%20%5Clim_%7Bn%20%5Cto%20%5C%201%7D%20%5Cfrac%7B2x%5E2%2B5x-7%7D%7Bx%5E2-1%7D%20%3D%20%5Clim_%7Bn%20%5Cto%20%5C%201%7D%20%5Cfrac%7B2%28x%2B3%2C5%29%28x-1%29%7D%7B%28x-1%29%28x%2B1%29%7D%3D%20%5C%5C%20%5C%5C%20%3D%20%5Clim_%7Bn%20%5Cto%20%5C%201%7D%20%5Cfrac%7B2%28x%2B3%2C5%29%7D%7Bx%2B1%7D%3D%5Cfrac%7B2%2A%281%2B3%2C5%29%7D%7B1%2B1%7D%3D%20%5Cfrac%7B2%2A4%2C5%7D%7B2%7D%20%3D4%2C5)
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