б) $$y = -\frac{4}{3x^2} + \sqrt{x}$$
$$y' = (-\frac{4}{3}x^{-2})' + (\sqrt{x})' = -\frac{4}{3} \cdot (-2) x^{-3} + \frac{1}{2\sqrt{x}} = \frac{8}{3x^3} + \frac{1}{2\sqrt{x}}$$
Ответ: $$y' = \frac{8}{3x^3} + \frac{1}{2\sqrt{x}}$$