214. y= √x/x³√x.

$$y = \frac{\sqrt{x}}{x^3 \sqrt[3]{x}} = \frac{x^{\frac{1}{2}}}{x^3 x^{\frac{1}{3}}} = \frac{x^{\frac{1}{2}}}{x^{3 + \frac{1}{3}}} = \frac{x^{\frac{1}{2}}}{x^{\frac{10}{3}}} = x^{\frac{1}{2} - \frac{10}{3}} = x^{\frac{3 - 20}{6}} = x^{-\frac{17}{6}}$$ $$y' = (-\frac{17}{6}) x^{-\frac{17}{6} - 1} = -\frac{17}{6} x^{-\frac{23}{6}} = -\frac{17}{6 \sqrt[6]{x^{23}}}$$ Ответ: $$y' = -\frac{17}{6 \sqrt[6]{x^{23}}}$$