Question

Помогите пожалуйста 15 по 20 с полном решением!!!

Answer 1

15) $lim_{x to 3} frac{x-3}{x^2-9}= lim_{x to 3} frac{x-3}{(x-3)(x+3)} = lim_{x to 3} frac{1}{x+3} = frac{1}{3+3} = frac{1}{6}$
16) f(x) = 2x + x^2
f'(x) = 2 + 2x; f'(2) = 2 + 2*2 = 6
17) $intlimits^2_1 {x^2} , dx = frac{x^3}{3}|^2_1=8/3-1/3=7/3$
18) не знаю
19) y = x^3 - 12x; y' = 3x^2 - 12 = 3(x^2 - 4) = 3(x-2)(x+2) < 0
x = (-2; 2)
20) y = x^4 - 2x^3; y' = 4x^3 - 6x^2; y'' = 12x^2 - 12x = 0
12x(x - 1) = 0; x1 = 0; x2 = 1