Вычислите

a) lim(n-->∞) (3^(1-n)+(6/n)-5)

б) lim(n-->∞) ((n+2)^2)/(4-2n^2)

a) = lim n->∞ ( 1/(3^(n-1)) + (6/n) - 5) = 0 + 0 - 5 = -5; б) = lim n->∞ ((n^2+4n+4)/(-2n^2+4)) = lim n->∞ ((1+(4/n)+(4/n^2))/(-2+(4/n^2))) = (1+0+0)/(-2+0) = -1/2