6)f(x)=4x^2+1/x-4*x/1/3 +x^2/5
f'(x) = 8*x -x^(-2) - 4*(1/3)* x^(-2/3)- (2/5)*x^(-3/5)
f'(x) = 8*x - 1/x^2 - 4/3* x^(-2/3)- (2/5)*x^(-3/5) (a)
Подставим в (а)
f'(-1) = 8*(-1) - 1/(-1)^2 - 4/3 * (-1)((-2/3)- 2/5*(-1)^(-3/5)
f'(1) = -8 - 1 - 4/3 + 2/5 = -9 - 4/3 + 2/5 - -9 - 14/15 = -149/15
7)f(x) = 1/((4*x^2 - 5*x))^3/7
Найдем производную сложной функции
f'(x) = 1*3/7(4*x^2 - 5*x)^(-4/7)*(4*x^2 - 5*x)' = 1*3/7(4*x^2 - 5*x)^(-4/7) *(8*x -5)=
=3/7*(4*x^2 - 5*x)^(-4/7) *(8*x -5)