Помогите найти пределы

6) (4-3x)/(34-3x) = (34-3x-30)/(34-3x) = 1 + 30/(3x-34);
(1 + 30/(3x-34))^(5-21x) = (1 + 30/(3x-34))^((3x-34)/30*(5-21x)*30/(3x-34)) ~ exp[(5-21x)*30/(3x-34)] ~ exp[-21*30*x/(3x)] → exp[-210] при x → ∞.

7) cos(3x) = 1 + (cos(3x) - 1), (cos(3x) - 1) → 0 при x → 0; (1 + (cos(3x)-1))^(11/x) = (1+(cos(3x)-1))^(1/(cos(3x)-1)*11/x*(cos(3x)-1)) ~ exp[11*(cos(3x)-1)/x] = exp[-22*sin^2(x/2)*(2cos(x)+1)^2/x] ~ exp[-16.5*x^2/x] → 1 при x → 0.