1. lim (при x->5) (sinx-sin5)/(x-5) = lim (2cos(x+5)/(2)*sin(x-5)/(2))/(x-5) = lim (2cos(x+5)/(2)*(x-5))/(x-5) = lim 2cos(x+5)/2 = 2cos5
2. lim (при х->1) (x^(1/2) -1)/(x^(1/3) -1) = ((x-1)(x^(2/3)+x^(1/3)+1))/((x-1)(x^(1/2)+1)) = 3/2
Правильно?