Вычислите производную : а)f (x)= 1/3x^9 + 2x^10 ; б)f (x) = 4/x (x^3 - 5) ; в) f (x) = x-1/x^3

А) f(x) = 1/(3x⁹) + 2x¹⁰
f'(x) = -3/x¹⁰ + 20x⁹

f(x) = x⁹/3 + 2x¹⁰
f'(x) = 3x⁸ + 20x⁹

б) f(x) = (4/x) * (x³ - 5)
f'(x) = (12x³ - 4x³ + 20) / x² = (8x³ + 20)/x²

в) f(x) = x - 1/x³
f'(x) = 3/x⁴