Lim[(6*4^n+1-3*2^(n+1))/(3*2^2n+1)]=lim](6*4^n-6*4^n-2*2^n)/(3*2^n+1)]=
=lim[(-2*2^n)/(3*2^n+1)]=lim[2^n*(-2)/(2^n*(3+1/2^n))]=
=lim[-2/(3+1/2^n)]=-2/3
Ответ А
В сантиметрах всё?
V конуса = 1/3 * ПR^2 * H
R^2 = L^2 - H^2 ( по теореме Пифагора)
R^2 = 196-144 = 52
V = 1/3 * 52 П * 12 = 208 П ( см^3)
![\displaystyle \tt 9x^2-144=0\\9x^2=144\\x^2=144:9\\x^2=16\\x=б4](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Ctt%209x%5E2-144%3D0%5C%5C9x%5E2%3D144%5C%5Cx%5E2%3D144%3A9%5C%5Cx%5E2%3D16%5C%5Cx%3D%D0%B14)
Ответ: х=-4; х=4
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Или так:
9х² - 144 = 0
(3х)² - 12² = 0
(3х+12)(3х-12) = 0
3х + 12 = 0 или 3х - 12 = 0
3х = -12 3х = 12
х = -4 х = 4
Ответ: х=-4; х=4
Это пропорция. Вот так 36___100
X____5
X=36*5
____
100
3^(5/6)*9^(1/12)=3^(5/6)*3^(1/6)=3^1=3